Counterparty trades actual bitcoins ('BTC') for XCP, and it has a much better order matching system.
Damn that's crazy.
Mastercoin is offering a 300 BTC bounty for such a feature, and it still isn't fully implemented.
PhantomPhreak = 2nd coming of Satoshi?
I will stay awake until I see the first Dex transaction with BTC. Don't wanna miss history.