diff --git a/src/java/com/samskivert/depot/DepotRepository.java b/src/java/com/samskivert/depot/DepotRepository.java
index 9013973..3bb6e26 100644
--- a/src/java/com/samskivert/depot/DepotRepository.java
+++ b/src/java/com/samskivert/depot/DepotRepository.java
@@ -32,7 +32,7 @@ import java.util.Map;
 import java.util.Set;
 
 import com.google.common.base.Function;
-import com.google.common.collect.Collections2;
+import com.google.common.collect.Iterables;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Sets;
 
@@ -182,12 +182,12 @@ public abstract class DepotRepository
      * @throws DatabaseException if any problem is encountered communicating with the database.
      */
     public <T extends PersistentRecord> List<T> loadAll (
-        Class<T> type, Collection<? extends Comparable<?>> primaryKeys)
+        Class<T> type, Iterable<? extends Comparable<?>> primaryKeys)
         throws DatabaseException
     {
         // convert the raw keys into real key records
         return loadAll(
-            Collections2.transform(primaryKeys, _ctx.getMarshaller(type).primaryKeyFunction()));
+            Iterables.transform(primaryKeys, _ctx.getMarshaller(type).primaryKeyFunction()));
     }
 
     /**
@@ -195,11 +195,10 @@ public abstract class DepotRepository
      *
      * @throws DatabaseException if any problem is encountered communicating with the database.
      */
-    public <T extends PersistentRecord> List<T> loadAll (Collection<Key<T>> keys)
+    public <T extends PersistentRecord> List<T> loadAll (Iterable<Key<T>> keys)
         throws DatabaseException
     {
-        return keys.isEmpty() ? Collections.<T>emptyList() :
-            _ctx.invoke(new FindAllQuery.WithKeys<T>(_ctx, keys));
+        return _ctx.invoke(new FindAllQuery.WithKeys<T>(_ctx, keys));
     }
 
     /**
@@ -227,14 +226,14 @@ public abstract class DepotRepository
      * @throws DatabaseException if any problem is encountered communicating with the database.
      */
     public <T extends PersistentRecord> List<T> findAll (
-        Class<T> type, Collection<? extends QueryClause> clauses)
+        Class<T> type, Iterable<? extends QueryClause> clauses)
         throws DatabaseException
     {
         return findAll(type, CacheStrategy.BEST, clauses);
     }
 
     /**
-     * A varargs version of {@link #findAll(Class,CacheStrategy,Collection)}.
+     * A varargs version of {@link #findAll(Class,CacheStrategy,Iterable)}.
      *
      * @throws DatabaseException if any problem is encountered communicating with the database.
      */
@@ -251,7 +250,7 @@ public abstract class DepotRepository
      * @throws DatabaseException if any problem is encountered communicating with the database.
      */
     public <T extends PersistentRecord> List<T> findAll (
-        Class<T> type, CacheStrategy cache, Collection<? extends QueryClause> clauses)
+        Class<T> type, CacheStrategy cache, Iterable<? extends QueryClause> clauses)
         throws DatabaseException
     {
         DepotMarshaller<T> marsh = _ctx.getMarshaller(type);
@@ -331,7 +330,7 @@ public abstract class DepotRepository
      * @throws DatabaseException if any problem is encountered communicating with the database.
      */
     public <T extends PersistentRecord> List<Key<T>> findAllKeys (
-        Class<T> type, boolean forUpdate, Collection<? extends QueryClause> clauses)
+        Class<T> type, boolean forUpdate, Iterable<? extends QueryClause> clauses)
         throws DatabaseException
     {
         return _ctx.invoke(new FindAllKeysQuery<T>(_ctx, type, forUpdate, clauses));
diff --git a/src/java/com/samskivert/depot/Ops.java b/src/java/com/samskivert/depot/Ops.java
index 90cd187..114febc 100644
--- a/src/java/com/samskivert/depot/Ops.java
+++ b/src/java/com/samskivert/depot/Ops.java
@@ -20,7 +20,7 @@
 
 package com.samskivert.depot;
 
-import java.util.Collection;
+import com.google.common.collect.Iterables;
 
 import com.samskivert.depot.clause.SelectClause;
 import com.samskivert.depot.expression.FluentExp;
@@ -49,9 +49,9 @@ public class Ops
     /**
      * Creates an AND expression with the supplied target expressions.
      */
-    public static FluentExp and (Collection<? extends SQLExpression> conditions)
+    public static FluentExp and (Iterable<? extends SQLExpression> conditions)
     {
-        return and(conditions.toArray(new SQLExpression[conditions.size()]));
+        return and(Iterables.toArray(conditions, SQLExpression.class));
     }
 
     /**
@@ -86,9 +86,9 @@ public class Ops
     /**
      * Creates an OR expression with the supplied target expressions.
      */
-    public static FluentExp or (Collection<? extends SQLExpression> conditions)
+    public static FluentExp or (Iterable<? extends SQLExpression> conditions)
     {
-        return or(conditions.toArray(new SQLExpression[conditions.size()]));
+        return or(Iterables.toArray(conditions, SQLExpression.class));
     }
 
     /**
diff --git a/src/java/com/samskivert/depot/SQLFragment.java b/src/java/com/samskivert/depot/SQLFragment.java
index 02a2989..9b3c56f 100644
--- a/src/java/com/samskivert/depot/SQLFragment.java
+++ b/src/java/com/samskivert/depot/SQLFragment.java
@@ -1,3 +1,6 @@
+//
+// $Id$
+
 package com.samskivert.depot;
 
 import java.util.Collection;
diff --git a/src/java/com/samskivert/depot/clause/SelectClause.java b/src/java/com/samskivert/depot/clause/SelectClause.java
index 7fef802..0891763 100644
--- a/src/java/com/samskivert/depot/clause/SelectClause.java
+++ b/src/java/com/samskivert/depot/clause/SelectClause.java
@@ -53,7 +53,7 @@ public class SelectClause
      * class for rows that match the supplied clauses.
      */
     public SelectClause (Class<? extends PersistentRecord> pClass, ColumnExp[] columns,
-                         Collection<? extends QueryClause> clauses)
+                         Iterable<? extends QueryClause> clauses)
     {
         _pClass = pClass;
         _fields = columns;
diff --git a/src/java/com/samskivert/depot/expression/ColumnExp.java b/src/java/com/samskivert/depot/expression/ColumnExp.java
index 0346477..560ae5d 100644
--- a/src/java/com/samskivert/depot/expression/ColumnExp.java
+++ b/src/java/com/samskivert/depot/expression/ColumnExp.java
@@ -55,7 +55,7 @@ public class ColumnExp extends FluentExp
     }
 
     /** Returns an {@link In} with this column and the supplied values. */
-    public In in (Collection<? extends Comparable<?>> values)
+    public In in (Iterable<? extends Comparable<?>> values)
     {
         return new In(this, values);
     }
diff --git a/src/java/com/samskivert/depot/impl/DepotTypes.java b/src/java/com/samskivert/depot/impl/DepotTypes.java
index c650acc..7e48090 100644
--- a/src/java/com/samskivert/depot/impl/DepotTypes.java
+++ b/src/java/com/samskivert/depot/impl/DepotTypes.java
@@ -23,7 +23,6 @@ package com.samskivert.depot.impl;
 import java.sql.SQLException;
 
 import java.util.Arrays;
-import java.util.Collection;
 import java.util.Map;
 import java.util.Set;
 
@@ -58,7 +57,7 @@ public class DepotTypes
      * are interrogated for their class definition sets through {@link SQLExpression#addClasses}.
      */
     public static <T extends PersistentRecord> DepotTypes getDepotTypes (
-        PersistenceContext ctx, Collection<? extends QueryClause> clauses)
+        PersistenceContext ctx, Iterable<? extends QueryClause> clauses)
         throws DatabaseException
     {
         Set<Class<? extends PersistentRecord>> classSet = Sets.newLinkedHashSet();
@@ -71,7 +70,7 @@ public class DepotTypes
     }
 
     /**
-     * A varargs version of {@link #getDepotTypes(PersistenceContext,Collection)}.
+     * A varargs version of {@link #getDepotTypes(PersistenceContext,Iterable)}.
      */
     public static <T extends PersistentRecord> DepotTypes getDepotTypes (
         PersistenceContext ctx, QueryClause... clauses)
@@ -84,7 +83,7 @@ public class DepotTypes
      * Create a new DepotTypes with the given {@link PersistenceContext} and a collection of
      * persistent record classes.
      */
-    public DepotTypes (PersistenceContext ctx, Collection<Class<? extends PersistentRecord>> others)
+    public DepotTypes (PersistenceContext ctx, Iterable<Class<? extends PersistentRecord>> others)
         throws DatabaseException
     {
         for (Class<? extends PersistentRecord> c : others) {
diff --git a/src/java/com/samskivert/depot/impl/FindAllKeysQuery.java b/src/java/com/samskivert/depot/impl/FindAllKeysQuery.java
index c64cf42..ae34965 100644
--- a/src/java/com/samskivert/depot/impl/FindAllKeysQuery.java
+++ b/src/java/com/samskivert/depot/impl/FindAllKeysQuery.java
@@ -21,7 +21,6 @@
 package com.samskivert.depot.impl;
 
 import java.util.ArrayList;
-import java.util.Collection;
 import java.util.List;
 
 import java.sql.Connection;
@@ -46,7 +45,7 @@ import static com.samskivert.depot.Log.log;
 public class FindAllKeysQuery<T extends PersistentRecord> extends Query<List<Key<T>>>
 {
     public FindAllKeysQuery (PersistenceContext ctx, Class<T> type, boolean forUpdate,
-                             Collection<? extends QueryClause> clauses)
+                             Iterable<? extends QueryClause> clauses)
         throws DatabaseException
     {
         _forUpdate = forUpdate;
diff --git a/src/java/com/samskivert/depot/impl/FindAllQuery.java b/src/java/com/samskivert/depot/impl/FindAllQuery.java
index d968c2c..d840c99 100644
--- a/src/java/com/samskivert/depot/impl/FindAllQuery.java
+++ b/src/java/com/samskivert/depot/impl/FindAllQuery.java
@@ -26,7 +26,6 @@ import java.sql.ResultSet;
 import java.sql.SQLException;
 
 import java.util.ArrayList;
-import java.util.Collection;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
@@ -66,7 +65,7 @@ public abstract class FindAllQuery<T extends PersistentRecord> extends Query<Lis
     public static class WithCache<T extends PersistentRecord> extends FindAllQuery<T>
     {
         public WithCache (PersistenceContext ctx, Class<T> type,
-            Collection<? extends QueryClause> clauses, CacheStrategy strategy)
+            Iterable<? extends QueryClause> clauses, CacheStrategy strategy)
             throws DatabaseException
         {
             super(ctx, type);
@@ -201,7 +200,7 @@ public abstract class FindAllQuery<T extends PersistentRecord> extends Query<Lis
     public static class Explicitly<T extends PersistentRecord> extends FindAllQuery<T>
     {
         public Explicitly (PersistenceContext ctx, Class<T> type,
-                           Collection<? extends QueryClause> clauses, boolean cachedContents)
+                           Iterable<? extends QueryClause> clauses, boolean cachedContents)
             throws DatabaseException
         {
             super(ctx, type);
diff --git a/src/java/com/samskivert/depot/impl/operator/In.java b/src/java/com/samskivert/depot/impl/operator/In.java
index 474ea82..756b140 100644
--- a/src/java/com/samskivert/depot/impl/operator/In.java
+++ b/src/java/com/samskivert/depot/impl/operator/In.java
@@ -22,6 +22,7 @@ package com.samskivert.depot.impl.operator;
 
 import java.util.Collection;
 
+import com.google.common.collect.Iterables;
 import com.samskivert.depot.PersistentRecord;
 import com.samskivert.depot.expression.SQLExpression;
 import com.samskivert.depot.impl.FragmentVisitor;
@@ -41,9 +42,9 @@ public class In
         _values = values;
     }
 
-    public In (SQLExpression pColumn, Collection<? extends Comparable<?>> values)
+    public In (SQLExpression pColumn, Iterable<? extends Comparable<?>> values)
     {
-        this(pColumn, values.toArray(new Comparable<?>[values.size()]));
+        this(pColumn, Iterables.toArray(values, Comparable.class));
     }
 
     public SQLExpression getExpression ()