Who You Know is a Sinatra app that let's a user create records representing contacts and interactions with those contacts to help you keep track of who you know and how you know them.
Check out a demo here.
To use this app, just clone, run rake db:migrate and then shotgun to get it running.
Bug reports and pull requests are welcome on GitHub at https://github.com/sgibson47/who-you-know.
The gem is available as open source under the terms of the MIT License.