BookMooch (my inventory) is international; PaperbackSwap (my shelf) is domestic only. I like the format of the PBS site better, but am slowly getting used to BM.
PBS has a "Box'O'Books" option -- you pay a nominal fee and, for a year, you can ask another boxer for several books off their shelf and offer them a look at your shelf for what they might like to swap. Good in theory, but I've had like three completed box swaps in the year. Most either want half-a-dozen "real" books and have nothing on their shelf but Harlequins, or they want to trade just one book -- getting around the "credit" aspect. I can understand that, but to me, it should be at least two books.
As an aside to this, I have a spitload of Harlequins headed for the burn barrel -- the UBS won't take them and they're not moving for trades, so if you want them yell. I'm not going to go through and list each one (go look on the sites! My inventory is linked.), but if you're looking for something specific (Title and Author) I'll check the pile.
Faire: I enjoy vending at White Hart, and this year was no exception. However, a lot of potential after-hour appointments fell through because of scheduling conflicts that had not been apparent in the planning stages. Next year, it's back to soap for me!