On my site you can vote for a game from 1-10. As is seems people are voting a lot more than once and voting down games just to bring their game higher. Is there a way I can restrict a person to 1 vote, or log the vote or something?
There are a few ways...
1) Cookies. These will hold back the casual cheater, but it is very easy to delete them.
2) By IP. Many people access the Web via proxy, such as AOL users or employees behind firewalls. So they would *all* be coming from one IP, and you'd overblock.
3) By GUID. This is a Globally Unique User ID, generated by many web servers. You should definitely look into this.
4) Blocking if the user-agent and IP are the same. This offers a bit better blocking than by cookie, but it'll still block out quite a few people it shouldn't be.