[ame=http://www.youtube.com/watch?v=csccfh80QZ8]YouTube - How To Run iPhone Apps Full Screen On iPad FullForce - Quick Tip #8 - iPhone Vlog 35[/ame]
This simple little download from Cydia will allow most of your iPhone Apps to run full screen on iPad. No, this isn't the X2 button, it's called FullForce. A free download where you have the ability to choose which iPhone apps you want to run full screen. With this tweak, you are also able to use the iPad keyboard on iPhone Apps.