I use twitter for various system stuff - and needed a way to get auth tokens for users for twitter oauth based apps.
Twitter provides PIN based authentication for this - you generate a URL based on the consumer token/secret - visit that - log in - get a PIN and use the PIN to generate the auth token/secret.
get_keys.rb is a simple ruby script to do just that.
It takes consumertoken and consumersecret as command line params (in that order), generates the authorize URL and prints it - then waits for the PIN. Displays consumer and auth token info at the end.