Thinking about cheap ways to lighten your bike - I just lightened my bike by 1/3lb in a matter of minutes by putting my lighter tires back on. I had my heavier Vittoria Open Pavè Evo CG (251g each on my scale) on for the Tour of Flanders a couple of weekends ago. I took them off and put my much lighter Schwalbe Ultremo ZLX(174g each on my scale) back on. Instant 154g savings. This is an often-overlooked place to shave off another few grams without breaking the bank, because tires that come on complete bikes off the showroom floor are often heavier. I see a lot of them coming with tires in the 240-250g range.

*According to the tire's specs, I've sacrificed some puncture resistance, but I haven't noticed - usually when I run over something, it's nasty enough to go through any bike tire, so I'm not too worried about it.