Big Ass Advertising
Eugene Volokh, who has forgotten more about commercial free speech than I have ever learned, cites a local government official's desire to outlaw a creative billboard that uses a donkey's hindquarters to sell large industrial fans.
The company, Big Ass Fans, took its name from its customers' spontaneous initial reactions to its up-to-24-foot diameter products. Big Ass Fans' marketing "guy" describes the marketing campaign as tasteful. I agree with Prof. Volokh that, while crude, this is certainly not obscene.