The Ruins of Murkhill: This is a great site for inspiration, house-rules futzing, and all around creativity.
Swords and Wizardry Discussion: The Discussion moves a little slowly, but the Play-By-Post section is rockin.'
Tenkars Tavern Common-Room: Sign up and meet new friends; this one is pretty new - but growing.
Swords & Stitchery - Old Time Sewing & Table Top Rpg Blog: Great reviews and plenty of goodies in the postings!
Canonfire!: Greyhawky Goodness.