The tale told by other Internet traffic trends (see Internet traffic tracking favors Obama), also rings true when taking domain registration into account. Using DomainTools to query for domains, we saw 2,357 domains for Obama and 1,431 domains for McCain.
When we stemmed the query to domains just having either "Obama" or "McCain" included in them, we saw 5,378 for McCain and 11,089 for Obama, However, the stemmed search (while it correctly mirrors the general trend) may be less accurate, because it can include situations in which the candidate's name simply happens to fit into another word.
Exploring the various domains registered reveals a mixture of pro and con sites for each candidate as well as their running mates. Some of the domains are likely run, or at the very least registered, by the campaigns themselves, in an effort to control message. However, many clearly are not. On this list of domains you will find: frank expressions of political support or opposition; home-spun attempts at political satire; and, lots of items (such as T-shirts) or services (such as candidate impersonation) for sale.
Like offline "retail" politics, online politics clearly attracts its fair share of popular humor and entrepreneurship. There are also a large number of inappropriate domains--notably crass, violent and sexually-related uses of the candidates' names. This seems to be particularly true for Obama and Palin, less so for McCain and Biden.
Interestingly, though, the GOP vice presidential candidate lacks the obvious domain registration (sarahpalin.com) at the time we wrote this report.