While I've not ever dropped-acid-and-burnt-wicker-men-alive (at least, not at Burning Man festival), from my understanding the event is meant to be somewhat of an escape from the humdrum of daily life. Meaning, you leave the iPhone at home.
That hasn't stopped an official Burning Man iPhone (and iPad!) app from hitting the store in time for next week's festival. The free app acts as a guide to "all the art, camps and events in Burning Rock City", though reports of it listing the best grass in the area are entirely unfounded.
While I did moan just a few sentences previously about how iPhones really shouldn't be taken out there, the developers have at least designed it to be used mostly offline, caching all the maps and information when the app is first used. [iTunes]