[I have a scroll button thing on my mouse, I just noticed that if you scroll it back and forth really fast, it looks likes everything is bouncing, only the background moves slower than everything else. This has been your information alert of the hour, Love, CtR] Miaow
Actually my computer wasn't working in my Web Design class once and, frustrated, I scrolled up and down reeeeaally quickly with that scroll button thing. When the computer started responding again everything did that 'bouncing' effect you described. omfg, my head hurt for the rest of the schoolday. ._.
Invent the drawing board to go back to. See, it is the truth. Seriously though it is amusing way to kill 5 minutes of boredom easily.