Bomomo is a Flash-based art application that runs in your Firefox or Safari browser. Instead of giving you some simple MS Paint-like tools like a paintbrush, bucket, and eraser, everything in Bomomo is dynamic and moving, leading to some kaleidoscopic creations that you can either e-mail to friends or squirrel away to your hard drive. If you know what you're doing you can create some really cool abstract creations.
What makes the tool particularly interesting is that each of the 18 drawing tools are tied to your mouse in a different way. Some tools will follow it around, while others do their best to escape your pointer--creating some genuinely gorgeous effects. Some also take advantage of where your pointer is, either changing in size or color based on what part of the screen you're on. It's also just plain fun.