Andrew Chen has used Google's Insights for Search system to plot the use of websites such as MySpace, Facebook, Digg and Twitter on a US map. Some cover the various states pretty well, and some are concentrated in California. Of the odd chart above, he says: "Twitter has a surprising profile - it's very strong within the states where it has any presence, but is basically dead outside of it."
Update: As Ciaran Norris points out in a comment (thanks!), TechCrunch has redone some searches with dramatically different results. TechCrunch's Erick Schonfeld comments:
Based on this data, there actually seems to be pretty broad-based interest in Twitter across the US -- with the possible exception of Wyoming. So what gives? It turns out that Chen included the ".com" at the end of each site's name when he created his maps ("techcrunch.com," "twitter.com," etc.). I can see why he might have done that -- to filter out any searches that were not for the sites themselves. But I think that method also cuts out a lot of relevant searches as well. Only nerds add the ".com" in the search box when they are looking for a site.
