URL Shortening App?

Anyone got recommendations on a good open source URL shortening app (ala tinyurl.com)to run at Flickr scale?

Its an easy enough problem thats its probably worth rolling your own, but I have to imagine there are one or two tricks.

Lazyweb, are you out there?

And yes, I know just asking this question means I’m walking perilously close to admitting that Dave might be right about something.

Photo by bies