I'm thinking of doing this too, but I don't have a frame yet. I've been talking about/getting advice about getting a new bike for months now but I just don't think I'm going to have enough money at any given time to buy a complete bike outright. I figure this will be a good learning experience, a way to get my bike exactly how I want it, & a pay-as-you-go option.
That said, anyone have advice on a decent cheaper frame to start with? What are our opinions on the Access XCL frame? Right now I'm looking at a budget of about $200 for the frame alone. It would be really nice to find a nicer used frame (I'm still drooling over the Jamis Komodo chelboed got me thinking about) but I don't know much about the frame-only market.