So much for getting any sleep tonight. There was an earthquake at 5:27 this morning, which was strong enough to shake the place up here on the 4th floor, and after the quake hit, there was a rolling aftershock. Definitely the strongest one I've felt since moving to Sunnyvale in 2003.
Preliminary results have the quake coming in at a 4.7... not too high, but more than 10 times stronger than the 3.5 we felt here a year or so ago - the previous "best".
USGS Update on the Quake | USGS Quake Map
I've yet to be in an earthquake that made me nervous, and have to admit we've enjoyed our minor to moderate quakes. Hopefully I can continue saying that in the future as well...