I chose to post this article because I think it does a nice job of breaking down this issue. First, the author describes some common web 2.0 tools, then she describes the barriers that people with disabilities might face in using those tools, and then she desribes a few ways that we can make web 2.0 tools accessible.

The writer of this article reviews some major blog hosts and discusses how accessible they are to people with vision impairments. Overall, he discusses how it is easier to read blogs than it is to create blogs for people with vision impairments. The reviews on different blogging sites are interesting. There is no date on this article, so it's possible that some of the blog sites have fixed these accessibility issues since the article was posted. However, I know that Blogger still has a visual CAPTCHA on its site that makes it difficult for people with visual disabilities to create an account.