I think the recap idea is right on the money. I usually start my games off with a brief "When we last left our adventurers..." segment to put everyone in mind of the last story. If one of the regular players has been absent, I'll usually make the others explain to him what he missed in character. Another thing that I do (that I picked up from Ross in his Actual Plays) is to remind the players of their goals and their options when they get a bit stuck. Players' memories can get a bit hazy between sessions sometimes, and it usually helps when you can give them a nudge forward. It lets them make their own decisions that will move your story along without making them feel like you're leading them by the nose.
I will admit that i have and still do use this method but unfortunately it take an awful lot of coaxing to kickstart their memories. Come to think of it maybe i was setting the bar too high, if they have trouble remembering what they did last session how the hell will they remember what they're supposed to be doing!
Almost drives you to running constant combat encounters because thats the only things they seem to remember (after coaxing).
'Oh man! You remember when you ran 20 yards across the compound and roundhouse kicked the guys head off?'
'...oh yeah'
In 20/20 Hindsight, I think you're right Ross. Blackmail is the way to go!
Now all I need is one of each of the player's relatives and duct tape.