Jason Kottke recently said he could spend all day watching Koen van Gilst’s Pong Wars, a JavaScript-based mashup of Pong and Breakout (designed by Steve Wozniak with help from Steve Jobs) that feels like a hyperactive digital lava lamp. Pong Wars features two balls, Day and Night, that bounce according to the physics of those games. The Day ball travels through light areas and turns dark blocks light, whereas the Night ball does the reverse, turning light blocks dark.