Well respected and established world-wide blogging initiative Global Voices Online was a first-click for many surfers and they are doing a great job with suggested links for further looking. They also have lots of videos.
I had to do quite a bit of zooming out before the Google map began including enough places I knew to give me some geographical context.
Evacuation photos aren't really as panicked as I expected. One blogger describes evacuated Beijing office workers as "bemused." Of course, when you don't know what's happening it's hard to know how serious to be. This blogger's eerie clip is a great example of that uncertainty.
If you're not impressed with the number of evacuation videos out there, here's a nice YouTube video showing what it was like to experience the quake itself. I'm not sure I'd hide under that counter like that guy's doing but I'm not one to judge. Glad they made it out.
Wikipedia is calling it the 2008 Sichuan earthquake. It's always interesting to watch breaking stories develop here in front of your eyes. A second ago someone replaced the entire story with pi written out to 10,000 place but that was quickly corrected.
Newsweek's Melinda Liu informs us that we can expect superstitious interpretations of this event. "Many Asians see major calamities as examples of "divine intervention" -- such as the recent Burmese cyclone which many citizens there interpreted as karmic payback for the military junta's bloody crackdown on monk-led protests back in September." I saw one page with photos of a mass frog migration from May 7 suggesting the frogs knew the quake was coming.
The Twtitter section:
A vast analysis of how news of the quake broke on Twitter.
The copious Tweeting by Robert Scoble on this story has some talking (seriously now, instead of speculatively) about Twitter journalism. Depending on when you click that Scoble link you may see what I'm talking about and you may see updates on whatever tech conference he's at right now. I suppose Twitter journalism works as a good live updater but as an archive to look through it's messy and impermanent. A problem Twitter doesn't address that was also a problem with blogs is that searching the service doesn't help separate the worthwhile first hand accounts from the people saying things like, "Hey, China had an earthquake." That said, when you look at the information in the main Global Voices story covering the event you see a lot of useful items with a Twitter link as the source reference.
Twitter Local is somewhat useful in helping find people on the scene. For example you can search for people Tweeting within 20 miles of Beijing.
Only distantly related but still really fascinating, ancient Chinese earthquake detection contraption. Any quake shakes the marble from the dragon's mouth whereupon it clangs into a metal cup.
I'll update as I find new things worth adding. Let me know if there's something I should include.