Lava lamps. I could watch these things for hours, and I'm sober! I can't imagine how many hours upon hours upon millions of hours were wasted in the 70s just staring at these lamps, watching them do their thing.

(Note: I can actually sit around for hours staring at a blue TV screen, so I guess I shouldn't be throwing stones. It's not that there's something extraordinarily comforting about the blue screen... it's just that I'm really, really lazy and I haven't been able to find my remote for a few days. I guess I'm glad I wasn't performing some national security-sensitive function in the 70s... I would have had one of these lamps in my office and been the Worst. Employee. Ever.)

But seriously, these things are cool. Always have been, always will be.