I was thinking about creating a public member that anyone could use. I'd lock his profile, so it couldn't be changed, but the username and password would become public, or maybe just available to the moderators, as a joke.

The more I think about it, the more it sounds like a bad idea, but I'm going to post this anyway to see what your thoughts are here.

It could be funny. It's like having the invisible "Gunther" when you play a card game...

Sounds... interesting
If anyone abused it you could check their IP of course...

I've considered creating a 'Yoda' profile for the purposes of interjecting appropriate Yodaisms into threads.