Total Recall is an extension of the Sinatra tutorial by Dan Harper, named Recall. It was developed as an exercise to learn how to use OmniAuth for Twitter authentication in a Sinatra application.
The original Recall tutorial can be found on Nettuts+.
Some code was lifted er taken directly from a post on Codebiff named OmniAuth with Sinatra.
As this was developed as an exercise there are probably some errors.