Are there any examples of a government department successfully using social media?

Quake Dave asked:


By social media, I mean things like Twitter, Facebook, MySpace, Youtube, blogs, and Wikipedia.
Any country or level of government is okay.
I’m doing a presentation and need some examples. Thanks.
Obama is an interesting example, but I’m thinking more along the lines of a department, rather than a specific individual or politician.

Las Vegas Internet Consulting