Shorthand for Oh really, orly, or o rly is used in chat rooms, games, and text-based communication in response to a comment. Often accompanied with an O rly owl or similar picture, it is a sarcastic response of disbelief.
User1: Ding! I finally just made level 60.
User1: what does grats mean?
People are also starting to use yrly, or ya rly, which is short for yes, really. Also, ya wai can be used for "yes way."