rev=canonical bookmarklet and designing shorter URLs
http://simonwillison.net/2009/Apr/11/revcanonical/

Bookmarklet that will 1st check canonical, if there is no shortURL, then it will create one using TinyURL

from simon willison's weblog.

A bookmarklet to extract rev="canonical" links from pages. I only use a few sites that support this at the moment (notably Flickr), but it's quite handy.

django-shorturls