I haven't tried my hand at painting on the IPhone yet but after seeing this cool art I will definitely start now. Remiscent of that old kindergarten activity, finger painting, (which I loved btw!) the BRUSHES app for IPhone and ipod touch allows you to turn your photos into very cool paintings. Here's some created by IPhone wiz, Jorge Colombo.
Watch the movie of how Jorge paints here. And hey, if I do get around to doing some iphone paintings myself, you will be the first to see them ;) Promise. IPhone painting - it's JUST COOL!