This is NOT MY PROJECT, I had NOTHING TO DO WITH IT, but I thought it was totally cool and should be passed around. In an interesting twist on the concept of a line-follower, this little guy looks like it’s using a needle to follow the grooves in a curved track made out of glued down pieces of broken-apart vinyl records:
As a plus, you don’t have to program buzzer music, interesting sound is produced just by driving the thing around!
Here’s the project link, which doesn’t have much more info, but includes a video.
-Adam