RE: [PHP] Unique user?

[snip] Is there any way of doing this: 1. User may vote 1-10 on a joke on a site X. 2. Same User may NOT vote again dependent of the computer... I know this works if I check IP-adress, but because some users doesn't have a fixed ip-adress... it won't work correct. Thought of getting a mac-adress, but I think is impossible to... :-) Any ideas? [/snip] Why not set a cookie? Now, we all know that users can delete cookies...but they typically do not do so. You could also make them register to be able to vote. That way they have to login before they vote and the vote would be tracked by username. They could register multiple names, but again they are not likely to do so.