Once authenticated to Twitter via OAuth I did not see a good call to get your username. How is this supposed to work? I'd like to pull back things like Twitter username, firstname, lastname, etc... basic profile stuff. Should the OAuth handshake give me my username?
Try this:
https://dev.twitter.com/docs/api/1/get/account/verify_credentials
It'll show you all information (you'ld normally get of any other user) of the OAuth-authenticated-account =)!