Here is the Big Bang Speaker from iwantoneofthose.com, which looks like a cartoonish bomb with a long fuse (the red audio cable). The Big Bang is designed acoustically and has two speakers. It offers a 3.5mm jack for connecting multimedia devices such as MP3 players, CD player, iPod, iPhone. It can be powered via USB or by four AA batteries.
The Big Bang Speaker is priced at GBP29.99.