Here are something interesting links for the earthquake fanatic:

Nor Cal USGS

Real Time Earthquake Maps (California-Nevada)

Real-time Shaking Maps for California earthquakes of Magnitude 3.5 and larger

1906 San Francisco Earthquake ShakeMaps

Earthquake Probabilities for the San Francisco Bay Area
USGS and other scientists conclude that there is a 62% probability of at least one magnitude 6.7 or greater quake, capable of causing widespread damage, striking the San Francisco Bay region before 2032.

General Quake Info
Earthquake basics and educational material; geological and historical information; links to professional and amateur organizations; online access to earthquake data.

Hazards & Preparedness
How to prepare your home, business and family for earthquake hazards; earthquake probabilities; shaking hazard maps; liquefaction hazard and earthquake engineering.

Earthquake Research
Current research activities and results in seismology, crustal structure and deformation, geology and borehole physics.

UC Berkeley Quake Site

Historical Earthquake Intensity Information

1868 Hayward Earthquake History:
http://www.museumoflocalhistory.org/pages/list.php?topic=earthquake
http://www.sfmuseum.org/hist1/1868eq.html
http://www.sfmuseum.org/hist4/68oakl.html
http://seismo.berkeley.edu/faq/1868_0.html
http://cires.colorado.edu/~bilham/HaywardCreep.html

California Department of Insurance – California Earthquake Information

California Reader: Stories about earthquakes

Hayward Fault Tour
A website showing the surface expressions of the Hayward Fault.

Paleoseismology, Hayward Fault, California
A large, widely damaging earthquake will occur on the Hayward fault in the future. That much we know. What we don’t know is when.

Predictive Intensity Map for 1868 Hayward Fault
This is the intensity distribution we would expect for a repeat of the 1868 earthquake which was a M=7.0 event on the Hayward fault.

Finally there is a great Google Earth Flyover of the Hayward fault put together by Jim Lienkaemper, a USGS geologist. Map showing active fault traces within the Hayward Fault Zone, including a virtual tour of the Hayward fault in the east San Francisco Bay Region that can be viewed in the Google Earth.