Ya know, I forgot perhaps my most important tool. After each session, I type up a 3-4 page "summary" of the events played out in the game. Its a short abbreviated narrative, and includes all the NPCs they met, clues they discovered, battles fought, items found... I try to get everything in there that the PCs would want to remember.
I email this out to my group, and they might get back to me with questions or clarifications. Its been a GREAT tool for keeping us all organized and interested.
Of course, we game only every other weekend at best, so I have time to indulge in this sort of nonsense. Usually... I'm a bit late on the current one...
-Reddist