iKaossilator
http://www.korg.co.uk/products/software_controllers/ikaossilator/sc_ikaossilator.php
iKaossilator for iPhone and iPod! $10 until end of November
There’s one Korg vid on YouTube showcasing it. Looks like fun but over priced @ $10 and that’s 50% off! But it beats spending $100-200 on a kaossilator