Might not be the cheapest but I was just purchasing another item from Orange and came across this. Because of it's size and connection I thought this was a great accessory to my phone whilst driving to get a sort of handsfree effect with clearer sound quality than on the phones loudspeaker.
The stylish Logic 3 Screenbeat USB Speaker produces exceptional clear sound quality, the twin drivers featured produce 3 watts power output. The ultra modern speaker has a frequency response of 200Hz -15Hz. The stunning speaker sits neatly in front of your computer and is powered via the USB port of your PC/Mac. The stunning, lightweight Screenbeat has a compact design featuring an aluminum shell, the speaker can easily fit into a laptop carry case for effortless transportation.
lightweight, compact design
3 watts power output
compatible with PC/Mac
powered via USB port
frequency response 200Hz -15Hz
size (H x W x D): 32mm x 206mm x 24mm