Check out these 14 pimped bikes (cool stuff, trust me) to get more ideas on the topic and maybe some ideas of how you could pimp your own bike.
This is really some kind of a new cult and I certainly wouldn't mind if the cars as status symbol would be replaced by some fantastic low riders. These bikes certainly have a lot of potential -- a recently published marvelous German rap video by Skero ft. Kamp proves that too. They sing about cruising around Vienna. Even if you don't understand German it's worth watching because of all the cool bikes involved and the lovely scenery :-). The title "Fuß vom Gas" simply means "Foot off gas [pedal]". Enjoy!