diff --git a/core/java/android/backup/AbsoluteFileBackupHelper.java b/core/java/android/backup/AbsoluteFileBackupHelper.java
new file mode 100644
index 0000000000000..ab246754b5afa
--- /dev/null
+++ b/core/java/android/backup/AbsoluteFileBackupHelper.java
@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) 2009 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.backup;
+
+import android.content.Context;
+import android.os.ParcelFileDescriptor;
+import android.util.Log;
+
+import java.io.File;
+import java.io.FileDescriptor;
+
+/**
+ * Like FileBackupHelper, but takes absolute paths for the files instead of
+ * subpaths of getFilesDir()
+ *
+ * @hide
+ */
+public class AbsoluteFileBackupHelper extends FileBackupHelperBase implements BackupHelper {
+    private static final String TAG = "AbsoluteFileBackupHelper";
+
+    Context mContext;
+    String[] mFiles;
+
+    public AbsoluteFileBackupHelper(Context context, String... files) {
+        super(context);
+
+        mContext = context;
+        mFiles = files;
+    }
+
+    /**
+     * Based on oldState, determine which of the files from the application's data directory
+     * need to be backed up, write them to the data stream, and fill in newState with the
+     * state as it exists now.
+     */
+    public void performBackup(ParcelFileDescriptor oldState, BackupDataOutput data,
+            ParcelFileDescriptor newState) {
+        // use the file paths as the keys, too
+        performBackup_checked(oldState, data, newState, mFiles, mFiles);
+    }
+
+    public void restoreEntity(BackupDataInputStream data) {
+        // TODO: turn this off before ship
+        Log.d(TAG, "got entity '" + data.getKey() + "' size=" + data.size());
+        String key = data.getKey();
+        if (isKeyInList(key, mFiles)) {
+            File f = new File(key);
+            writeFile(f, data);
+        }
+    }
+}
+
diff --git a/core/java/com/android/internal/backup/SystemBackupAgent.java b/core/java/com/android/internal/backup/SystemBackupAgent.java
new file mode 100644
index 0000000000000..6b396d777a664
--- /dev/null
+++ b/core/java/com/android/internal/backup/SystemBackupAgent.java
@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2009 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.internal.backup;
+
+import android.backup.AbsoluteFileBackupHelper;
+import android.backup.BackupHelperAgent;
+
+/**
+ * Backup agent for various system-managed data
+ */
+public class SystemBackupAgent extends BackupHelperAgent {
+    // the set of files that we back up whole, as absolute paths
+    String[] mFiles = {
+            /* WallpaperService.WALLPAPER_FILE */
+            "/data/data/com.android.settings/files/wallpaper",
+            };
+
+    public void onCreate() {
+        addHelper("system_files", new AbsoluteFileBackupHelper(this, mFiles));
+    }
+}
diff --git a/core/res/AndroidManifest.xml b/core/res/AndroidManifest.xml
index 0c90769d97914..db31818694f01 100644
--- a/core/res/AndroidManifest.xml
+++ b/core/res/AndroidManifest.xml
@@ -1000,6 +1000,7 @@
                  android:hasCode="false"
                  android:label="@string/android_system_label"
                  android:allowClearUserData="false"
+                 android:backupAgent="com.android.internal.backup.SystemBackupAgent"
                  android:icon="@drawable/ic_launcher_android">
         <activity android:name="com.android.internal.app.ChooserActivity"
                 android:theme="@style/Theme.Dialog.Alert"
diff --git a/services/java/com/android/server/BackupManagerService.java b/services/java/com/android/server/BackupManagerService.java
index fdd4617b58a43..efa617943e174 100644
--- a/services/java/com/android/server/BackupManagerService.java
+++ b/services/java/com/android/server/BackupManagerService.java
@@ -76,8 +76,7 @@ class BackupManagerService extends IBackupManager.Stub {
     private static final boolean DEBUG = true;
 
     // Default time to wait after data changes before we back up the data
-    private static final long COLLECTION_INTERVAL = 1000;
-    //private static final long COLLECTION_INTERVAL = 3 * 60 * 1000;
+    private static final long COLLECTION_INTERVAL = 3 * 60 * 1000;
 
     private static final int MSG_RUN_BACKUP = 1;
     private static final int MSG_RUN_FULL_BACKUP = 2;
@@ -360,7 +359,8 @@ class BackupManagerService extends IBackupManager.Stub {
         if (DEBUG) {
             Log.v(TAG, "Adding " + targetPkgs.size() + " backup participants:");
             for (PackageInfo p : targetPkgs) {
-                Log.v(TAG, "    " + p + " agent=" + p.applicationInfo.backupAgentName);
+                Log.v(TAG, "    " + p + " agent=" + p.applicationInfo.backupAgentName
+                        + " uid=" + p.applicationInfo.uid);
             }
         }
 
diff --git a/services/java/com/android/server/WallpaperService.java b/services/java/com/android/server/WallpaperService.java
index 5532894b0f0d2..d921bafe7101d 100644
--- a/services/java/com/android/server/WallpaperService.java
+++ b/services/java/com/android/server/WallpaperService.java
@@ -18,8 +18,10 @@ package com.android.server;
 
 import static android.os.FileObserver.*;
 import static android.os.ParcelFileDescriptor.*;
+
 import android.app.IWallpaperService;
 import android.app.IWallpaperServiceCallback;
+import android.backup.BackupManager;
 import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
@@ -154,7 +156,16 @@ class WallpaperService extends IWallpaperService.Stub {
     public ParcelFileDescriptor setWallpaper() {
         checkPermission(android.Manifest.permission.SET_WALLPAPER);
         try {
-            return ParcelFileDescriptor.open(WALLPAPER_FILE, MODE_CREATE|MODE_READ_WRITE);
+            ParcelFileDescriptor fd = ParcelFileDescriptor.open(WALLPAPER_FILE,
+                    MODE_CREATE|MODE_READ_WRITE);
+
+            // changing the wallpaper means we'll need to back up the new one
+            long origId = Binder.clearCallingIdentity();
+            BackupManager bm = new BackupManager(mContext);
+            bm.dataChanged();
+            Binder.restoreCallingIdentity(origId);
+
+            return fd;
         } catch (FileNotFoundException e) {
             if (Config.LOGD) Log.d(TAG, "Error setting wallpaper", e);
         }