Vox, Craigslist, Technorati and other San Francisco-based Web services have gone down because the power's out in downtown San Francisco. You'd think they'd have a better backup plan.

I'm not sure how to monitor and record all the outages of Web 2.0 startups that are happening (will the founders Twitter each other and share the tally?) but it would be a great exercise. Online services pitch themselves as an essential part of your Web-connected life, so this ought to be a learning experience similar to the one Seattle techies experienced last December.

On the positive side, those browned-out companies have really cut their carbon footprint, unless they're firing up gas generators to get the lava lamps going again.

UPDATE: Add to the list Six Apart and Red Envelope, which proudly announced two years of uptime just before the power went out, David Geller pointed out on his WhatCounts blog.

ANOTHER UPDATE: Former Seattleite Corey Lewis emailed from San Francisco to point out a Valleywag item about alleged trouble at an SF server facility that a lot of these companies use, but the bigger problem was the result of an electrical line failure.