Im not into downhill, I do dirt jumping and street riding. Like bad azz gaps and drops and all that. But my dad has a sweet down hill bike he built a few years ago. Id like to build a free ride bike though!
I ride a Specialized 09 P1, so far I have odyssey plastic pedals, Bandanned seat, ditched the front brake, and a few little things. Got the weight down to 29 pounds, so not bad. I can bunny hop 3 feet up with it

So im happy with the weight, for now
And also, if you want to get on some sweet forums,
http://www.ridemonkey.com/forums/index.php
Crappy cell pics, in my buddies messyyyyyy backyard lol. The black one is my buddies mirraco 24.