So, I'm putting together a list of other uses for Twitter (besides alerting people as to when you're having lunch). I came across this use today, Twitter for traffic, after my hellacious 2 hour commute from Simi to Santa Monica this morning. Traffic on the 405 was miserable and started backing up on the 118. Why?
I get to my desk and decide that I want to know what the hell happened to my normally 60 minute commute. Then I remembered... Twitter has the public posts and is pretty much real-time (something Google is envious of and trying to duplicate). Let's see who else was pissed off about this. So I search for 405 traffic. Then it hit me, what if I could subscribe to an RSS feed of tweets for a specific search on Twitter that would help alert me to rough conditions on the 405! Fortunately, they have a set of APIs that will allow you to do that, and much more. Included is a GET method for searching the public timeline, output in either JSON or Atom. You basically just include a hashtag, up to 16 characters, at the end of this URL... http://search.twitter.com/search.atom?q=405%20traffic. This then let's you incorporate the Atom feed into your favorite reader (like Google Reader).

As you can see from the screen cap above, taken at 1:15pm, this is at worst 45 min delayed. So, if you have an iPhone or other mobile device where you can get your feeds, subscribe to "405 traffic" or "101 traffic" or "91 accident" or whatever works for you. Then check this out before you leave for work in the morning or on the way home. Wish I would have known this before. Could have taken PCH!
Side note: Traffic sucked because the President Obama motorcade needed the entire 405 to get to LAX (of course). AND HE WASN"T EVEN IN THE MOTORCADE!