One of the most prevalent uses for blogging that I come in contact every day is are blogs written by news columnists and political cartoonists. It seems that any regular contributor to a newspaper, magazine, or even broadcast news outlet consistently updates some sort of blog. One of my favorite such sites is Daryl Cagle's Political Cartoonists Index. While primarily a site that collects current political cartoons, there is a great blogroll on the right side of the site where contributors take the opportunity to both analyze trends in political cartoons and have discussions on topics relevant to what cartoonists are drawing about. One of my favorite current posts is by Will Durst, called "Trickle-Up Economics." Here, Durst comments on the current "Class War" debate that was started with President Obama's introduction of the "Buffet Rule." I have to agree with Durst's conclusion that perhaps Obama should fight the rhetoric by using terminology like "trickle-up economics."
Such blogs, I think bring to mind two ways blogs could be used in the social studies classroom. First, students could start their own RSS feeds (of both liberal and conservative columnists) and follow a couple columnists' views throughout the school year. The other use I see is having students contribute to a class current events blog, where they themselves have the opportunity to synthesize news stories and commentary.
Both of these uses offer a couple of challenges that I have already identified. First, students will need lessons on bias and editorials in order to help them understand points of view and the difference between opinion and fact. Second, students would need a strong background in how to cite sources - perhaps such a blogging assignment would be best done in coordination with their English classes.