Implementing a voting system without requiring registration

Question

I\'d like to implement a voting system on my site, without having to force them to create an account. They would ultimately be voting up/down a piece of content which has a

Answer 1

Yes, you could use a cookie and set the expiration very far into the future; however, there is nothing stopping anyone from clearing their cache and voting again.

Your best bet, is to use the cookie and don't allow votes from the same IP within 15 minutes of each other... without registration thats the best you can do.