Tutorial - http://www.youtube.com/watch?v=fxzHPyRgEKM - or:

To install this, you must download it from a computer and then upload it onto your idevice in the following directory:

/var/mobile/Applications/Cut the Rope/Library/Preferences

This is one of many edited PLIST files that hack your games. This package will unlock all cut the rope levels and get an automatic three stars on all. Enjoy!