It's interesting to see the wave of URL shorteners spawned by the constraints Twitter put on its payload. Is the thinking that it's safer for individual organizations to have their own shortener rather than rely on the bit.ly's and tinyurl's of the world because in the future they'll be able to change where they point (e.g. if they adopt a new CMS with different URL scheme)?
Interesting that they chose to save 3 characters on their short URLs via the tiny domain name, but are wasting 4 by using only numeric characters in their story slugs.<p>Nine numeric characters provide for a possible set of 1 billion unique story IDs. You can get roughly the same size set with five alpha numeric characters (even more if you toss in a couple of symbol characters).