These have good reviews and the red, blue and pink ones are at what looks like a decent price.....
Active Speaker System for iPod, PSP & MP3 players
Powered by 4 x AAA Batteries (Supplied)
Innovative compact folding design & holding system
Supplied with 3.5mm to 2.5mm Stereo converter for Mobile Phones
4 Watts Total Output
32mm neodymium drivers
Complete with protective travel case
The lightweight and compact design of the i-Station Traveller allows you to listen to your favourite songs wherever you choose.
Powered by 4 X AAA batteries (supplied) connect the i-Station Traveller to your portable audio device via the 3.5mm stereo line-in cable to produce clear quality room filling sound. Small enough to fit into your pocket, the i-Station Traveller is complete with a protective travel case, a mains power connection and a 3.5mm to 2.5mm Stereo converter