If you're under 25 you might find this tough to accept, but back in the '70s and '80s people used to actually pay good money to go sit in a tent, and watch a laser light show that was inevitably choreographed to Dark Side of the Moon. Of course certain pharmacological enhancements were usually necessary to get the full effect.

Now for $25 you can recreate the same experience at home, (chemical enhancements not included), using the Red Hot Laser Light Show. What used to take a whole truckload of gear, now runs with just four AA batteries, projecting spheres, lines, and shapes across your walls and ceiling. A built in microphone picks up the beat from whatever Pink Floyd album you happen to be playing, and moves the laser patterns in sync with the music.

Scientifics, via Oh Gizmo!