A bunch of teams post here when they're recruiting. Find one that posts, show up the day of their recruitment, impress them with your play.
Otherwise, find where teams that you like play, and simply show up and play on days they practice (usually sunday). Talk to them and find out if they need an extra member, even if it's only as a backup for an upcoming tourney. Because of the weak economy and the expense of the sport, if you have the money to reliably practice with a team, right now is a great time to get on them, because many players are having to either scale back their playing, or stop doing tournies altogether to focus on being able to eat.