Mitt Romney Has A Campaign Ad On Santorum's Vulgar "Google Problem" Website
That's right. Mitt Romney has an ad on Dan Savage's favorite website, "Spreading Santorum". Also worth noting is that the ad is from Romney's campaign (as opposed to a PAC). (Thanks to Gabriel Laks for the heads up!)
And a closer look at the ad shows that it is "Paid for by Romney For President, Inc."
Update: As some have mentioned this is likely an instance of the Romney camp buying keywords and having it bite them in the ass, rather than a direct ad buy at "Spreading Santorum."