The enormous head stares at traffic headed east on Colfax with a cold, smarmy sneer. There's something about this man that you just don't trust. Maybe it's his surly glare, or maybe it's just the giant lettering next to him that asks, "Who Invited Syphilis to the Party?" Jesus, that's a little direct, isn't it? But we've all seen it a million times. The night is in full swing, second keg just got tapped, and then in walks Syphilis, covered in lesions, with swollen lymph nodes and patchy bald spots on his head. Nobody will fess up to inviting him, but he's there just the same, and he's ready to party. This billboard is positioned so creepily -- above the Guardian Angels' headquarters and kitty-corner from one of the most high-traffic prostitution spots in the city -- that many passersby just might heed the advice to "Get Tested" and call the prominently displayed number. Now, that's what we call a party favor.