I have long been using URL shorteners as a tiny tool easy to implement in whatever Web language/toolkit catches my attention of the day. I even have a working Go implementation on BeeGo + Gorm somewhere.
But this time, I wanted to do it differently, and scoped most of the features of a full-fledged API for this, as well as a SQL data model for it. It clearly was not meant as an actual submission, more of a pretext to hack along for two days with fellow Gophers in Paris and kick off actual development.
It turned out these two days allowed me to implement even less than I had expected : just a part of the long/short URL table handling ; but with passing integration tests, and no non-runtime dependencies except the MySQL driver.
I will probably continue extending it after the challenge, though, so if the subject is of interest to you, feel free to send issues or PR's.
Oh, by the way, Kurz is german for "short" :-)