Pencil is an animation/drawing software for Mac OS X, Windows, and Linux. It lets you create traditional hand-drawn animation (cartoon) using both bitmap and vector graphics. Pencil is free and open source.
TouchArt Sampler is a great way to learn the art and skills of performing live visuals and VJing. TouchPlayer and 21 interactive 2D and 3D animations (synths) are included in this sampler. Touch lets you manipulate visuals in real-time, giving you control of various parameters like lighting, color, textures, motion, video playback, and composing. Play some audio and you can sync visuals to the BPM.