This package enables fast-registration to users owning an account with any of these services:
Github and Salesforce are planned
User can associate with more than one service. They get a normal user account and a password is automatically sent to their email.
The package doesn't override core files, so it will work in next releases.
It uses HybridAuth libraries so that middle-experienced developers can hack code to post news, ecc.
You will need to setup an app to use some of these services (eg. AOL or Twitter). Instructions are provided while adding.