Well, you're supposed to be able to set a website title and URL in your profile (under Forum Settings), but this feature is currently broken. When I set those fields, it sticks for a few minutes, and then disappears.There could be a (valid) concern about spammers setting up account profiles with nasty links. I have suggested that it be dependent upon your post count.Setting the website field in the Personal Info seems to work for me... I'm not sure if it will stick.
Well, I just discovered that it was just a missing "http://" in the forum profile settings that was causing the problem. I had "www.youtube...", but with "http://www..." it is working!