Goo.gl URL Shortener by Semimagic:
Google just opened their Goo.gl URL Shortener to the public, and in honor of the occasion, I whipped up a Safari Extension that will quickly shorten the URL of the currently open tab using Google’s service. The Goo.gl Safari Extension is free and (mostly) open source.
Via http://safariextensions.tumblr.com/post/1251072538
