main page - login as guest or anonymous

from the main page,
http://labelme.csail.mit.edu/Release3.0/

I don't see a way to just start using it, without having to faff around with registration (email, passwords, usernames).

it would be better if you can just dive in. You could still record the IP of contributions, tag them as 'anonymous'/'guest' or whatever, and retroactively validate them (if clients want to filter contributions from trusted sources). Given 'anonymous contributions' a 10% weighting or something, if you're worried about a higher probability of damage