It sounds like what you're doing isn't working, which may be stating the obvious but the only option you have is to try something different... Maybe he's enjoying the vocal responses and he's doing it to get more attention out of you. You could try silently picking him up and locking him in the bathroom, if he meows let him, ignore it until he stops then let him out.. if he doesn't stop after an hour or so let him out anyway and if he jumps to bite you again put him straight back in for another hour.
Another thing you could try if it is that drastic is one of those compressed air cans you use to clean out your computer:
http://tektype.files.wordpress.com/2010 ... ed-air.jpg I've never had to use one as a disciplinary tool but I do have one at home and can confirm our kitten hates it, other people seem to have decent results using this or water spraying (our kitten loves water so it wouldn't work). Then there is things like Feliway which people seem to have mixed results from.. I can't really recommend this because I haven't tried it, maybe others can though.
In the mean time I wish you all the best.. I would probably be covering my legs to the point where he can't break the skin, at least then I could laugh at him for trying while I try to diffuse the situation instead of having to deal with pain induced rage...
Good luck!