On: Confirmed: Digg Just Hijacked Your Twitter Links

They should just fold the functionality into their API. Add an optional URL field to each tweet, and then within the message the URL can be referenced using Markdown like syntax: [link body][1]. Only the link body text would count against your character count, so you get a free URL.

They could even sell the click-through analytics to their large customers.

URL shorteners are a hack, there's no reason to encourage them any further.

Precisely. I have no idea why we can't do this - Twitter already supports # and @, there's no reason they can't support URLs in the same manner.