diff --git a/core/src/main/scala/spark/ParallelCollection.scala b/core/src/main/scala/spark/ParallelCollection.scala
index 9725017b61..4bd9e1bd54 100644
--- a/core/src/main/scala/spark/ParallelCollection.scala
+++ b/core/src/main/scala/spark/ParallelCollection.scala
@@ -2,6 +2,7 @@ package spark
 
 import scala.collection.immutable.NumericRange
 import scala.collection.mutable.ArrayBuffer
+import scala.collection.Map
 
 private[spark] class ParallelCollectionSplit[T: ClassManifest](
     val rddId: Long,
@@ -24,7 +25,8 @@ private[spark] class ParallelCollectionSplit[T: ClassManifest](
 private[spark] class ParallelCollection[T: ClassManifest](
     @transient sc : SparkContext,
     @transient data: Seq[T],
-    numSlices: Int)
+    numSlices: Int,
+    locationPrefs : Map[Int,Seq[String]])
   extends RDD[T](sc, Nil) {
   // TODO: Right now, each split sends along its full data, even if later down the RDD chain it gets
   // cached. It might be worthwhile to write the data to a file in the DFS and read it in the split
@@ -40,7 +42,12 @@ private[spark] class ParallelCollection[T: ClassManifest](
 
   override def compute(s: Split) = s.asInstanceOf[ParallelCollectionSplit[T]].iterator
   
-  override def preferredLocations(s: Split): Seq[String] = Nil
+  override def preferredLocations(s: Split): Seq[String] = {
+    locationPrefs.get(splits_.indexOf(s)) match {
+      case Some(s) => s
+      case _ => Nil
+    }
+  }
 }
 
 private object ParallelCollection {
diff --git a/core/src/main/scala/spark/SparkContext.scala b/core/src/main/scala/spark/SparkContext.scala
index d7b46bee38..7ae1aea993 100644
--- a/core/src/main/scala/spark/SparkContext.scala
+++ b/core/src/main/scala/spark/SparkContext.scala
@@ -194,7 +194,7 @@ class SparkContext(
 
   /** Distribute a local Scala collection to form an RDD. */
   def parallelize[T: ClassManifest](seq: Seq[T], numSlices: Int = defaultParallelism): RDD[T] = {
-    new ParallelCollection[T](this, seq, numSlices)
+    new ParallelCollection[T](this, seq, numSlices, Map[Int, Seq[String]]())
   }
 
   /** Distribute a local Scala collection to form an RDD. */
@@ -202,6 +202,14 @@ class SparkContext(
     parallelize(seq, numSlices)
   }
 
+  /** Distribute a local Scala collection to form an RDD, with one or more
+    * location preferences for each object. Create a new partition for each
+    * collection item. */
+   def makeLocalityConstrainedRDD[T: ClassManifest](seq: Seq[(T, Seq[String])]): RDD[T] = {
+    val indexToPrefs = seq.zipWithIndex.map(t => (t._2, t._1._2)).toMap
+    new ParallelCollection[T](this, seq.map(_._1), seq.size, indexToPrefs)
+  }
+
   /**
    * Read a text file from HDFS, a local file system (available on all nodes), or any
    * Hadoop-supported file system URI, and return it as an RDD of Strings.