iWant an iPad for this:
http://www.youtube.com/watch?v=OEiJFNO1E5g
(Yeah it's not a great demo, and the guy is annoying, but gives you an idea..)
I used to play with this program on the PC a decade ago, when I found it had been 'ported' to the iPhone, I got excited but the screen was just too small.... now it's on the iPad....awesome.
iPhone/Pads are awesome for making music.
Have an awesome synthesizer app on the phone called NLogSynth... if your into that sort of thing, get it... the free version is awesome.
EDIT:
Okay, a better demo of what can be done...
http://www.youtube.com/watch?v=ykJiT90PnMY
This is an awesome track and shipped with ReBirth for the PC as a demo a decade ago. Genius stuff.
More:
http://www.youtube.com/watch?v=qKqXk6QBHro
(from 1:00 on.... 4:50 on is a cover of Drax Amphetamine)
Pretty much anything done by T.G.Virus for ReBirth is awesome.
EDIT2:
Haha, how many times can i say '
awesome'?