You can see the permissions for the current domain in Tools > Page Info > Permissions

That does not help if you blocked someone and at a later point want to unblock them, unless you can find ALL of the sites then this is a time consuming process. A search function would be MUCH easier.

There is a search for passwords, I think there should be a search for cookies.

Did you try to click in the exceptions window and type the first letters of a website ?

Yes, the only options are block, allow for session, and allow, remove site, remove all sites. So if I know the EXACT address I can type in the entire thing, but that is not a search function.

If you click in the pane witch the files names then you can search by typing the first letters of a domain (e.g. google or www.)

That helps somewhat, but as I stated not all sites start with www, so it is still not a really good search. I guess that what I was trying to do was make a suggestion that this "feature" be added to new versions of the software, but as you are the only one to respond, I guess it will never happen as no one else has the issue, or even thinks it is a good idea.