Hi there... on my site it lists links to other sites. I want the user to be able to click a button to mark any site they have visited. From then on a small icon will load up next to that link whenever they visit that page again.

I was thinking maybe I should use cookies to store which sites have been visited/marked (using site ID's which I could then check up against a MySQL database). But the user might end up marking hundreds of sites, would the cookie get too big in that case? Should I be looking at another way of doing this?

any help is appreciated
thanks -rich