NiSEE - Earthquake Engineering Abstracts, EQIIS Image database, strong ground motion database
Seismo-Surfing
All Things Seismological - SSA
Geotechnical Earthquake Engineering Server - Reconnaisance reports from recent earthquakes, among other things
NEIC's Near Real-time Earthquake Bulletin
FEMA Documents: 350-353 356 368
USGS Seismic Hazard Maps

Fun Stuff:

Tour of the Hayward Fault
Exploratorium's Life Along the Fault Line - lots of videos, footage from Loma Prieta, pictures from 1906