I certainly don't have the money currently to cop any apple products, but this application from Audio Realism is almost enough to make me strongly consider an iTouch. Check the video below, and find out more info on their page
I know we all geek out about new technologies, VSTs and ever more complicated ways to do things, but sometimes creativity will smack you in the head and hang out in your crib for days when you smoke a l'il something or drink a little something, and jam on pattern-based devices!