When Naheed Nenshi was campaigning for mayor of Calgary, he used Twitter and other social media extremely well. He was obviously tweeting/etc himself, rather than letting his PR committee handle it for him (as all other candidates appeared to do). Now that he's been elected mayor, he's still showing how to use social media effectively.
He's the mayor of a major Canadian city, and he still makes time to engage with citizens on Twitter and other social media. Not as a way to manage spin, but as a direct democratic channel.
It's his job. This is how it's done. I fracking love this guy.
(tweet conversation captured by [jkozuch](http://twitpic.com/34axmv) )