With the release of Tweetie 2 for iPhone yesterday, it is now possible to use Linkee as your default shortener, and have all your statistics tracked as well.

Here's the url to enter into Tweetie's custom shortener field:

http://api.linkee.com/1.0/shorten?api_key=[your-api-key]&format=text&input=%@

Your Linkee API key is at the bottom of My Account page (if you have an account).

For those of you without accounts - sign up! It's free!  Alternatively, just remove the "api_key=" parameter.

http://api.linkee.com/1.0/shorten?format=text&input=%@

Also - It seems like Tweetie doesn't automatically shorten the links for you - you must tap the number counter and choose shrink links. It also appears to only shrink links that are long enough.