Have you heard of Flower Mound, TX? It's one of the most advanced towns in the country as far as its website is concerned. I like their use of Google Calendar.
There's a lot of new uses for social networking being implemented at all levels of government. The State Department opened up its new Exchanges site with Facebook pages, online video, with forums, blogs, and hosted pages at connect.state.gov. I'm expecting more use of social networking from FEMA soon as well. In fact, with everything being promoted at change.gov, I expect a lot more agencies trying to get an early start on what they expect will be the future direction.
Social networks are becoming more integrated at the user level, with many tools that allow you access to all your networks through a single tool on your mobile device. I really like Vlingo which allows you to post voice activated updates to Twitter and Facebook. Check out what Don Tapscott, author of Grown Up Digital, has to say about the coming impact of social networks on government in this video: