Matt
pointed me to
Kaillera, a networked
version of MAME.
Play
classic arcade games online!
Alas, the public servers are full of people playing dumb punch/kick
games. Can't wait to try this out.
Like all cool software that seems vaguely illicit, Kaillera has some
association with
Nullsoft.
The download is hosted there and the Kaillera author credits Justin
Frankel for the
net code.