For a well thought out approach to dealing with earthquakes, consult "Seven Steps to Earthquake Safety" by Earthquake Country Alliance. I also highly recommend CERT training -here in earthquake country, specific measures for EQs are prominent. I keep a gas valve wrench in my CERT pack.

I mentioned earlier about the brief appearance of crummy emergency supply kits in stores immediately after a shaking event. One exception appears to be the local REI, which regularly stocks what appears to be a fairly decent emergency kit, although I am a staunch adherent of DIY for items like this.