iPhone - de Blob
I found a great little game for the iPhone. Basically you're this little blob guy who can absorb paint and then roll around and smash into buildings to paint them. It's coming out for the Wii and DS later this year as well. It's got some pretty decent graphics and good use of the accelerometer/tilt feature.
It's only $6.99 (dropped from it's original $9.99 price) so if you want a nice, fun and colorful game to mess around with, I'd recommend it.