In direst emergency, the BMan org says:
If somebody you know is attending Burning Man and there is a death in the family, or similar circumstance that necessitates contact, please call information in Northern Nevada and get the phone number for the Burning Man office in Gerlach. We will use our resources to find the needed party. If you know the name of the camp or group the person is with, that is helpful information.
I certainly hope you won't need to contact me that way, but if you do, I'm camping with Snack Food Glory Hole on Allante near 9:00.
If you are actually going to be in Black Rock City, you should, by all means, drop by Snack Food Glory Hole at A&9:00. And if you've come all that way, you should definitely get on your knees, put your mouth to the hole, and receive a snack. No, you should, I swear.
If you want to send me USPS mail, there's a chance it'll get to me (full page with details):
Snack Food Glory Hole
Allante & 9:00
Gerlach, NV 89412
If you want to send me email that some nutty person might turn into art and deliver to me, follow the directions on this page, which I am too lazy to read and then retype.
And if, like most people I know, you just want to make note of all the awesome things you do while I'm away and tell me about them in person when I'm back, that, too, will delight me.