[Edit Description]
Flickr have started their own URL shortening service, specific to their own domain.
The service uses the http://flic.kr domain name. So far I have noticed that individual photo pages each have a short URL that look like so http://flic.kr/p/EKD8 at present you can find the short url for a photo by viewing the source code of the page it is on. it will looks something like this <link rev="canonical" type="text/html" href="http://flic.kr/p/EKD8? > its quite near the top of the page.
I wrote a quick bookmarklet, tested on Mozilla Firefox, Google Chrome and Internet Explorer that lets you quickly send the shortened version of the photos URL to the twitter messaging service.
Source (steeev.freehostia.com)
[Edit Javascript]
Show Source Code
javascript%3Aif%2520%28location.href.match%28/flickr%5C.com%5C/photos/%29%29%7Bls%3Ddocument.getElementsByTagName%28%27link%27%29%3Bfor%28i%2520in%2520ls%29if%28ls%5Bi%5D.rev%3D%3D%27canonical%27%29%2520%7Blocation.href%3D%27http%3A//twitter.com/home%3Fstatus%3D%27+ls%5Bi%5D.href%3B%7D%7D
flickr twitter
