I was talking to a friend the other day who was building up a bike. He asked me how to choose the right stem length. After finding out that he may have to swap out his first choice to get the right fit, he wondered out loud if eBay was chock full of barely used bike stems being sold by new bike owners. Maybe. Purelycustom.com is trying to change that. They've got adjustable stems and cranks that they machine and anodize. The price is steep, but not so steep that a team, club or shop couldn't buy them and use them to fit riders bikes. The cranks work in a unique and non-obvious way. The left crank adjusts at the crank hub and the right crank adjusts at the spider. You'd think they would have made telescoping shafts, but the adjustment mechanism then probably couldn't withstand the load of someone who needed 185mm crank arms!
pictures form http://www.purelycustom.com/