Full Tilt Poker, guaranteed prize pool events on March 12th.
Full Tilt Poker are running several tournaments on Saturday including ones for poker players that prefer low stakes:
Early Double A: 4pm ET, $5000 guarantee, $6 entry fee
Daily Double A: 9pm ET, $8000 guarantee, $12 entry fee
There are also tournaments running in other formats, for example there is a Pot Limit Omaha Hi event available at 9:15pm ET ($24 + $2).
For players that prefer high stakes there is a $100,000 Guarantee running at 3pm ET with an entry fee of $300 + $22. Satellites are available for the event for players that want to try to get into the main draw cheaper.