Question inspired by this tweet:
bit.ly still doesn't support OpenID? Any recommendations on a url shortener that does? http://twitter.com/jongalloway/status/17967007628
Try this one http://twurl.cc/ I am not sure how it works but I do know they accept only openIDs for logging into their system.
Here is a list of what were the top 15 URL shorteners as of Jan 20th of this year, http://www.gadgetcage.com/2010/01/top-15-url-shortening-services-to.html