I'm not sure about other sites for setting up priv. tourneys.
I've got some friends of mine here in town where I live who regularly hold games online, making them the min. buyin so that tourney fees are small and then pool their cash in a separate prizepool off of the site (games are typically $20 or $50 apiece). Kind of a neat way to set up a homegame where everyone stays at home, lol. I guess you could do it 'Battleship' style and have everyone show up with their laptops, lol. Battleship format is pretty funny... have tried it before, looking across the top of other's screens in an effort to pick up tells
but usually turns into more of a comedy fest.