I would think that bitcoins would be a great fit for websites that allow for gambling, and with Texas Hold 'em being such a big card game it seems that a Hold 'em site might allow players to use bitcoins to fund their accounts. Does anyone know of a reputable poker site that accepts bitcoins?
The best resource to look for a poker site is the gambling section on bitcointalk.org. There are a lot of smaller sites advertised in that section of the forums trying to cater to the poker players who want to use their bitcoins.
I think I've also seen people will to trade bitcoins for money on bigger poker sites, but I do not believe any major sites accept bitcoins directly at this time.
I have used BTC On Tilt a few times and I like it. They have a nice interface and constant free rolls during the day.
as of this writing there is only one site to play bitcoin poker on, and that's sealswithclubs.eu - they have games running almost all the time / very fast cashouts / no contest
Switch Poker is a real money poker site, and it accepts bitcoins:
I'd second http://betwithbtc.com/ as a good resource for gambling related bitcoin sites.
Along with the bitcoin centric poker sites mentioned in other answers switchpoker.com takes bitcoin as a payment method along with other more traditional payment methods.