The great idea was brought up here for gamers, past and present alike, to host a GaryCon this weekend.
If you're reading this and would like to dive back in, but don't have your old D&D stuff, let me offer a few free tabletop RPGs you can download off the 'net and quickly get to playing!
Basic Fantasy (link): Should be familiar to those who played Basic/Expert D&D!
d20SRD.org: All the rules you really need for the latest released version of D&D/d20 in one hypertext-linked location!
OSRIC (link): For those who loved 1st Edition AD&D!
More interested in Space and Sci-Fi? Check out:
Star Frontiers (link): This website offers free and legal downloads of the old TSR classic, Star Frontiers.
Icar (link): A free, comprehensive sci-fi RPG for those looking to engage in a bit of Space Opera.
Encounter Critical (link): Was your gaming pure craziness back in the day? Encounter Critical, an RPG That Never Was, is perfect for your gonzo madness (while you're there, if you're looking for some beer-n-pretzels light gaming fare, check out Risus).
There are many more free (and excellent commercial) RPGs out there--this is just a short starter list. If you have an old favorite and or aren't sure about what you might need, just ask! Let's get our geek on!
EDIT: HinterWelt is offering their OGL module, Turris Lemurum, for free until Sunday in support of this idea. Class act.