I have suggested this before, but I'm not entirely sure why it wasn't done... I think Ash said that Rich couldn't figure it out or something, but here we go anyway;
1. Create new board section, call it "The BOT Arena"
2. Create new forum user group "authorised user"
3. Create another new user group "n00b"
Make all new user sign-ups require mod/admin approval to be "upgraded" from n00b status to authorised user status.
n00bs can only post in The BOT Arena, which will obviously include bots.
Authorised Users will have access to the entire boards.
n00bs must post in The BOT Arena in order to get our attention, and give us an opportunity to laugh and mock them. Once we have satisfied our thirst for being a bunch of meanies, we can let them into the real forum.
Should we find an especially cool Bot, we can create yet another user group called Mascot, and let it post in OT... and he must have this signature image:
This would in turn, eliminate the need for the "Are you human?" test entirely.