I tried selling BTC for MP today for my first site-based trade.
I found this thread: https://bitcointalk.org/index.php?topic=247634.0 in which it seemed like people had successfully traded with this dude today. (I think, but am not sure, that the 'successful trades' were just dummy accounts to make it look like he had actually traded.) I messaged the guy, he responded right away, so I sent BTC: