It is possible to learn by blogging. I've previously discussed Hume's notorious footnote and Beattie's response to it, and noted that you can find a useful, if somewhat uneven, discussion of the footnote in a paper by Eric Morton. In addition I've given a resource or two on the subject of Francis Williams, the Jamaican poet who is casually libelled by Hume in the footnote. As I've noted before, I think this an important issue, one that needs to be considered more often than it is; at the very least, it raises questions that need to be considered seriously. What had somehow slipped my notice, though, is that Kant makes use of the footnote; what called it to my attention was this post at "Musings of a Postmodern Negro," which I found while surfing the blogosphere. If you want the background to the Kant quote, you can find that online as well. Thomas Teo has a brief discussion of Kant's racism in the context of critical psychology; and Matthew Hachee has a brief discussion of it in the context of ethics. Laurence Thomas (PDF) has a truly excellent discussion of it in the context of moral psychology (Thomas, by the way, is a blogger).
On a slightly different but somewhat related note, see Nathanael Robinson's interesting discussion of Race and Progressives at "The Rhine River."
(BTW, Chris Clarke of "Creek Running North" has suggested that bloggers treat December 1, the 50th anniversary of Rosa Parks's act of civil disobedience in Montgomery, as Blog Against Racism Day. HT: Majikthise)