Think Progress has put together NetTrends '08 to track the presidential race.

From now through the end of the 2008 election, NetTrends will be tracking how the candidates and their supporters are using the Internet. We'll be updating the site regularly, and will direct you to the must-see web content we find. There's also a handy graph making it easy to see who's utilizing the Net and who's not.

Why track the ‘08 candidates online? Because conservatives have long dominated the traditional media battlegrounds of radio, television, and direct-mail. With Rush Limbaugh and Fox News leading the charge, they enjoy a "wide-ranging, multimedia apparatus that when tapped will vibrate like a gigantic tuning fork."
[..]Check out our database HERE (and other great work being done by TechPresident) - and please share sites and resources that you think are particularly useful and innovative.