Gadget store ThinkGeek just listed inflatable speakers.
The Inflatable Speakers broadcast sound in all directions. These things are ideal for BBQs or other outdoor events. They are not water proof though, so forget about having them float around in your pool. The speakers can be powered via the battery pack or through AC. These inflatable speakers have 10W power.
Get a pair for $39.99 on ThinkGeek.
We reported the first time about inflatable speakers back in early 2003.