CardRunners and StoxPoker are offering free poker training online, just for playing poker.
The only catch is you have to play on Full Tilt (not much of a catch if you already play there), and you must earn 4500 Full Tilt points in a month to receive a free month membership to CardRunners (2500 points for StoxPoker). And best yet, you keep your points. All that's required is earning that many base points in a month.
You also need to be a current paying member of CardRunners or StoxPoker, which you can buy with Full Tilt points.