Here in Los Angeles, there's a cataclysmic event about to happen. No, it's not the next earthquake (as far as we know) or an alien invasion. It's Carmageddon, which is what the locals have started calling a closure period over July 16 and 17 where the city will shut down the 405 highway from the 10 to the 101. That's a huge stretch of road in a city that depends on its cars, so people are expecting the fallout to be pretty monstrous -- while lots of folks (including me -- my apartment is about two blocks from the 405 on Santa Monica) are hoping to just stay home for the weekend, we've all got places to go and things to do, so we may end up navigating the traffic anyway.
iPhone app Waze is helping to jump on this grenade -- the company has teamed up with Los Angeles' KABC 7 to bring real-time traffic updates to and from the iPhone all throughout Carmageddon weekend, both using its social mobile network of users (which just recently hit 4.5 million drivers around the world) to track movement on the road, but also to connect the TV station with volunteer users, who can report where reporters might not actually be. The company's set up an anti-Carmageddon website, and hopes to provide alternate routes and information to frustrated drivers all weekend long.
I hope it helps -- this particular stretch of the 405 is about six lanes wide, and serves about 500,000 people on any given weekend, so presumably all of those people will be off the highway and looking for other streets to use. Fingers crossed that it's not quite as apocalyptic as it seems it might be.