penders - 11:18 am on Nov 22, 2011 (gmt 0)

I'm wondering if it's possible to block a certain domain from setting a cookie...

Third party cookies? You wouldn't be able to block these without blocking the entire script or setting exceptions in the browser itself I would have thought.

For your own cookies... As enigma1 suggests, this does sound very problematic, unless perhaps you only presented a controlled subset of cookies to your users. You'd probably need some kind of cookie to store which cookies are blocked!? Unless your users are particularly concerned about which cookies are set (although I'm not sure why they should be) then it would perhaps be best to control functionality at a higher level.