I am trying to create vote up and down arrows similar to what exists here on Stack Overflow. Ideally I'd like to have them interact dynamically with a piece of text recording the number of votes, just as they do on Stack Overflow.
Unless there's some trick I hadn't considered, I'd think you'd need to create a many-to-many relationship between users and the items being voted on.
Every time someone votes up or down, you'd add a record to the joining table. This is the only way I see to track which user has already voted and be able to track both the number of up and down votes--like stackoverflow does.