How about a speaker than does that but only runs on 2 x AAA batteries?
If the answer is yes - how about a price point of only £15?
My son recently bought a mighty Boom Ball at the Gadget Show live to use in his bedroom to listen to music from his iPod shuffle.
The boom ball is a vibration speaker with a battery boost that attaches via a sticky pad to any surface. The kit contains a couple of spare pads, the boom ball and a battery booster pack (batteries not included).
The speaker does exactly what it says in the box and does turn any surface into a fairly decent speaker.
I am extremely impressed with this little unit and think the sound quality is excellent particularly when used with a hollow tube (from an Easter egg).