What's the point in distribuing your public key through the same channels as a signature? Kinda defeats the purpose. Esp since I can't verify that the given public key is indeed yours, since you're anonymous.

Well, there's some point in it. If I send an anonymous message, sign it with a key, and then include that key you can use that key to verify that it indeed was the key used to sign the message. For this to be of any value, however, future messages should be signed with that key but should not include it. This just proves that the person who wrote the last message is the same guy who wrote the first. That's about the only poitn I can see, though.