At the end of last week, the editors at LAist posted that the site would be migrating to a new server over the weekend. Always frightening words. As of Monday at noon, the site is not back up (or at least the LAist.com address isn't working). I believe they have tech help back at the Gothamist mother ship in New York so I trust they'll be running again shortly. The banner ad is now appearing on Defamer, I notice.
* Update: They're back.