some suggests on making the CALDERA (oh of course from the audience) lighter:

wheels: you can change the tires (MEC has the PANARACER smoke and dart which are well priced and actually quite light compared with the other tires).
don't forget lighter tubes too.

seat ands seat post, also not very expensive to change.

these are the cheapest to change i think. the next "price range" i think would be changing hubs, and rear cassettes and chain rings, but you would have to do them ALL if you want any significant change in weight.

good luck and happy riding!

Han