Mountain Biking Sydney Australia

customizing my bicycle?
can somebody give me ideas on how to customize my bicyle, its just a normal mountain bike and i want to make it more beautiful and increase its functions
i need a cheap way to do it for a teenage boy..
im in australia Sydney so local websites or shops can help me..
thanx
this question is open to anyone, anywhere not just for australians
ok dont mind the function now just the beauty is ok
I put black and yellow insulation tape around my bike – bar ends, frame, down-tube etc. I also put small pieces of reflective tape wherever I could on the frame. Both of these features were
1) cheap
2) looked quite cool
3) acted as a warning to people and made me more noticable on the roads
4) lasted for a long time
5) could easily be removed if I got fed up with it.
Insulation tape is cheap as chips and can be found in any shop that sells tools, electrical bits and bobs and so on. Reflective tape is around in most bike shops.
Mountain Bike Action @ Oxford Falls Sydney