One improvement that could be made to Mozilla’s cookie interface, is a picklist/checkbox interface on siteload to allow one to allow per-cookie/session control for blocking cookies. The core functionality is already there (see the cookie manager), it just needs an interface tweak. Currently you’re forced to guess which cookies you want to block because the per/cookie dialog that pops up doesn’t tell you what the cookies being sent actually are!
Ah, jr points out there’s a bug on this very topic. His idea is to have a cookie icon on the status bar which would open up this dialog box. I’m assuming it’d be similar to IE’s P3P icon. I was thinking about something less modal, and a sidebar would work (with a flip-out option a-la searches).
Further thoughts: creating a procmail-like regexp filterset for cookies might be useful, but would create an esacalating arms race w/ marketeers encouraging the further obsfucation or even misrepresentation of cookie id’s / content-types. (i.e., you only accept ASP session ID’s on URLs with .asp extensions? then I’ll just rename my tracker cookie ASPSESSIONID* and rename my PHP content types on my server to execute in my .htaccess.) Sure it’ll be obscure at first (it probably would already exist except for the sad state of cookie managment in browsers has largely made this unneccessary), but eventually it’d filter out, just like most of the morons spamming don’t understand the first thing about MTAs or RFC protocols. They just buy the spamming tool that does it for them and click the button.