I found this great device today while reading T3 magazine.
It basicly feeds music from any source which has a 3.5 headphone socket out into the local area as FM radio waves. So what this basicly means you can listen to the music on a ipaq via any radio tuned to the right frequency.
I've also been thinking of ways of abusing this device like taking over someones radio by tuning the device to match there current frequency. This would be great when you get some Kevin in there supa'ed car with loud music playing from a radio station. Because you could replace there music with something of your own choosing. The same would work when your noisy neighbour is playing there radio too loud. Change it to something of your choosing. Excellent, I love the smell of hacked hardware.