Did you know there is a preference pane in your Mac’s System Preferences called Internet Accounts? Internet Accounts acts as a central repository for your major internet service accounts. Though you can set up accounts for your email services inside Mail, and set up Twitter and Facebook logins on the web, you can do all those things within Internet Accounts and the services will become much more globally available.

To get a sense of why you’d want to do that, spend a few minutes reading the linked article.