Do you do a lot of linking? Do you e-mail links to your friends often. Then the copyurlplus extension for Firefox is just for you.
The Copy URL+ extension enables you to copy to the clipboard the current document's address along with additional information such as the document's title, the current selection or both. You might find this behavior useful when you want to send (IM, email) an interesting link to a friend and out of laziness convenience you don't want to copy the link and an explanation of what the link is in a single step. The explanation can be as short as the document's title or it can be a descriptive text from the document.
Copyurlplus is a free download, and works everywhere Firefox does (Mac/PC/*nux).
copyurlplus [Mozdev]