I stumbled upon a great collection of smileys on this website. It includes a lot of the ones we already have here, and some interesting variations.

I especially like this one which I suggest be coded as ":peternorth:"

and ":benenglish:" (not that you can actually tell the genders)

Tony, any chance of getting some of these? Could we just "borrow" them? Are smileys assumed to be in the public domain?