Free GM Resource: Masterplan
Masterplan is an "Adventure Design Studio" that is basically a scratch-built database for GMs to set-up and record their campaigns. If I wasn't attempting to do the same with a wiki, I'd be all over this.
After watching the five tutorial videos I can say that Masterplan seems a helluva lot easier to use than what I'm currently doing, and it seems to do a better job on every level but one to the alternatives I've used. I have a specific requirement that I might just need to re-evaluate in favor of switching over to Masterplan.
The program is written with D&D 4E in mind, but the author had to remove the game-specific libraries so I don't see how this couldn't be a great asset for any game.
Masterplan is a small (< 6 MB) download that you should check out. My GM buddy uses it just to create a working custom calendar and says it is worthwhile just for that.