Ever since I got the iPhone I have been obsessed with Apps, and this one just reaffirms my obsession. 
Check out the "Last Night Never Happened" App.

This God send allows you to erase everything you did online including "unwanted and embarrassing posts from your Facebook and Twitter accounts, including photos, comments, tweets and direct messages" says the app.  

Example- you wake up in the morning and realize you went on a crazed rant on Facebook about your ex, your friends, or whoever. Simply go into the app and dial the clock back Marty McFly style. POOF. Never happened. 

Worth way more than its download price.