LEAKED: HOW TO UNLOCK WORLDS IN ANGRY BIRDS

You can unlock the different worlds of Angry Birds without having to beat each level by following a few easy steps, see below.  The player will still need to beat each level to advance in the world but with this method you can start new worlds without finishing the old ones.  This has only been reported to work with the Android version so far. [Android Community]

Here's how to do it:

1. Go to a World Select Screen
2. Center a locked world on your screen
3. Hit the back button on your Android phone until you exit Angry Birds
4. Load Angry Birds back up
5. When you see the 'Play' button, tap the button repeatedly
6. You're now inside a locked world