To save your API create an account
Mashape allows you to consume and monitor APIs in your Application, giving you a one stop shop for monitoring, payments, and management.
Facebook Graph API. (For demo purposes only). You can also use FQL using the "fql" parameter. You need to create an app in https://developers.facebook.com/apps to get this to work (check the Readme section)
Get your API keys & start hacking!