For one, Mr. Buffett is a ukulele enthusiast but doesn't appear to play guitar.

WSJ: No Song, or Dance, for Buffett

Also, Sting has designed some kind of overgrown ukulele that's friendly to the rainforest because it doesn't use much wood.

ENGADGET: Music Thing: Singing speech synthesizers

Robotic Ukulele Players: Mike and Jarvis' reggae-playing Ukulele robots were widely reported earlier this year, but they weren't the real pioneers.

ENGADGET: Music Thing: Musical instruments made of Lego