the kids here have a new hobby: pimp my bike.
last year we saw all the light effects on the bikes (colourfull turning lights, flashing turninglights while breaking, lamps under the bike and in the wheels)
now many turn there bike into a sound machine. speakers, tft - screens, dvd player, subwoofer ... everything you normally would expext in a car.
sounds like a lot of fun ;-))))

... and tops my thought about riding the bike with mp3 sound ....

you can find a short video here

or right here