The Your in America Bot (@YourInAmerica) searches out every tweet that proclaims "Your in America, speak English" -- or some variant of that proclamation -- and, well, corrects them. Witness the awesomeness:
It's "you're." Also, we speak English. RT @testcase2try Your in America, so your supposed to speak American people.— Your in America Bot (@YourInAmerica) November 27, 2012
The person(s) behind this geniosity are truly after this grammarnerd's heart.
Added irony -- the bot will most likely correct this post when it's title is tweeted out to my Twitter followers.