Worked around JavaScript bridge exception for Android 2.3. Use "prompt" instead of calling objects directly. There were several objects called from JavaScript, including BrowserKey, so key events had to be reworked.

framework/src/com/phonegap/App.java

@@ -3,7 +3,7 @@
  * MIT License (2008). See http://opensource.org/licenses/alphabetical for full text.
  * 
  * Copyright (c) 2005-2010, Nitobi Software Inc.
- * Copyright (c) 2010, IBM Corporation
+ * Copyright (c) 2010-2011, IBM Corporation
  */
 package com.phonegap;
 
@@ -17,7 +17,7 @@ import com.phonegap.api.PluginResult;
  * This class exposes methods in DroidGap that can be called from JavaScript.
  */
 public class App extends Plugin {
-	
+
     /**
      * Executes the request and returns PluginResult.
      *
@@ -45,6 +45,16 @@ public class App extends Plugin {
             }
         	else if (action.equals("addService")) {
             	this.addService(args.getString(0), args.getString(1));
+            }
+        	else if (action.equals("overrideBackbutton")) {
+            	this.overrideBackbutton(args.getBoolean(0));
+            }
+        	else if (action.equals("isBackbuttonOverridden")) {
+            	boolean b = this.isBackbuttonOverridden();
+            	return new PluginResult(status, b);
+            }
+        	else if (action.equals("exitApp")) {
+            	this.exitApp();
             }
             return new PluginResult(status, result);
         } catch (JSONException e) {
@@ -132,4 +142,32 @@ public class App extends Plugin {
     public void addService(String serviceType, String className) {
     	this.ctx.addService(serviceType, className);
     }
+    
+    /**
+     * Override the default behavior of the Android back button.
+     * If overridden, when the back button is pressed, the "backKeyDown" JavaScript event will be fired.
+     * 
+     * @param override		T=override, F=cancel override
+     */
+    public void overrideBackbutton(boolean override) {
+    	System.out.println("WARNING: Back Button Default Behaviour will be overridden.  The backbutton event will be fired!");
+    	((DroidGap)this.ctx).bound = override;
+    }
+
+    /**
+     * Return whether the Android back button is overridden by the user.
+     * 
+     * @return boolean
+     */
+    public boolean isBackbuttonOverridden() {
+    	return ((DroidGap)this.ctx).bound;
+    }
+
+    /**
+     * Exit the Android application.
+     */
+    public void exitApp() {
+    	((DroidGap)this.ctx).finish();
+    }
+
 }