Pherotones are ringtones that will make you "irresistible to the opposite sex." They're basically like pheromones, but they work via sound rather than scent. They're also a hoax. According to NewsTrend.com, the website promoting them is part of a viral marketing campaign dreamed up by the McKinney-Silver ad agency. NewsTrend writes:

The first mentions of Pherotones began around December 30, on "Dr. Vanderhood's" Pherotones blog, where the good doctor began posting "an ongoing diary of the life of a scientist on the verge of a major breakthrough." The JoniMueller blog caught wind of the Pherotones blog and posted about it on January 16. The real story began to break on January 18th with an Oreilly interview with Vanderhood.

The strange thing is that no one knows what this stealth marketing campaign is for. It seems a bit useless to attract all this attention, and then blow it by not revealing what you're advertising. (Thanks to Thilo for the link.)