Favstar is an online service which tracks Twitter

Twitter

Twitter is an online social networking and microblogging service that enables its users to send and read text-based posts of up to 140 characters, informally known as "tweets".Twitter was created in March 2006 by Jack Dorsey and launched that July...

 and Twitter usage

Twitter usage

Ever since the inception of Twitter on July 15, 2006, there has been many notable uses for the service, in a variety of environments.-In Policing:...

. Favstar uses data from user "favorites" - or when a Twitter post is bookmarked (starred) by individual users. As posts, or tweets, are given more stars, specific posts move up in rankings

Game ladder

A ladder tournament is a form of tournament for games and sports. It is an extended tournament, which can potentially go on indefinitely. In a ladder tournament, players are listed as if on the rungs of a ladder. The objective for a player is to reach the highest rung of the ladder...

 according to different criteria, including recent posts, newer posts, and all-time favorites. Favstar uses open authorization

OAuth

OAuth is an open standard for authorization. It allows users to share their private resources stored on one site with another site without having to hand out their credentials, typically username and password.OAuth allows users to hand out tokens instead of credentials to their data hosted by a...

as a means to sign in.