10-minute-URL-Shortener is a project mainly written in Ruby, it's free.
A URL shortener using Sinatra and deployed on Heroku
A Ten-minute URL Shortener - implemented using the steps described in http://blogs.sitepoint.com/2010/09/28/a-ten-minute-url-shortener/
Following the steps described in this page, I deployed my first application on Heroku! (Modified the functionality a bit to make http://growing-samurai-36.heroku.com get redirected to this blog : http://zero2railshero.tumblr.com )
Also, tried out my hand at writing rspec tests for the first time!