One of the most common dismissive gestures I read on the interweb blog-tubes goes something like, "You don't even have the guts to put your name on your opinions." It becomes a cudgel when all else--logic, reason, politesse--fails and an argument can't be won on its merits.
I have little sympathy for this argument, even when we're talking about truly anonymous comments. I allow them here, and for the most part it isn't a problem. Any given comment thread here has few to no participants calling themselves "anonymous." Even those who do generally remain within bounds of acceptable discourse.
Other blogs also allow anonymous comments, and, again, usually there's no problem with what those folks say. But my main beef with anonymous comments is easily demonstrable in, say, just about any long thread at Shark and Shepherd: You get a number of different people posting as "anonymous" and it's hard to keep track of who says what.
A much better approach, I think, is to go the pseudonym route--a blogonym, if you will--and label yourself with something readily identifiable. A good pseudonymous blogger or commenter is, in my mind, no different than one who uses his or her real name. You become a recognized entity as your pseudonym, so people can get to know you, what you write, and how you think.
There are plenty such pseudonymous bloggers and members of the commentariat on both sides of the Cheddarsphere, even more if you extend it to people using just a first name. I got no beef with them, and I don't particularly care if I know their real names or not. Resorting to that real-name argument is just dumb in such cases, especially considering the long history our country's political discourse has with pseudonymity.