Can you make a voting/rating system without logins?
snokleby: At http://tagdef.com I let users both add content and vote without login in. It uses IP-addresses for keeping track of votes.This has all the flaws that other people here have pointed out (multiple users behind same IP etc), but I feel that the advantage of being easy to use is greater than these disadvantages. It serves it main purpose (most of the time), of putting good content on top (see e.g. http://tagdef.com/ff) and hiding bad content.