You can specify which web sites are allowed or denied to load various types of contents, such as Image, Script, Cookie, in one exceptions management window.
In other words, this is permissions.sqlite editor.
Firefox has simple site-based content blocker. You can allow or deny access to content by site and type, such as Image, Script, Cookie, from browser option.
Fortunately, Firefox2 stored these settings in a text file "hostperm.1", so you could edit/import/export host and policy table. But Firefox3 stores these in a binary database file "permissions.sqlite". Instead of a text editor, this add-on will help you.
Cookie, Install, Image, Popup, Script, Document, Dtd, Object,
ObjectSubRequest, Ping, Refresh, Stylesheet, Subdocument, Xbl,
* Firefox's blocking function does not support some of these types.
You can import/export "hostperm.1" format text file.