Have you a got a webcam? You can try Glow Doodle out! Painting with Glow Doodle is like taking a long exposure photo, where you draw with streaks of light, but you see the results in real-time.
Paint with your cellphone! Paint with your teeth! Paint your body with light!
Press space to automagically upload pics right here. Now with top-secret time-travel face-melting mode (press t).