Burning Man, the annual festival that celebrates art, counterculture, and radical self-reliance, begins Sunday in the Black Rock Desert of Nevada. The weeklong event has long drawn a wild crowd that eschews modern society and technology in favor of partying and constructing strange buildings in the middle of the desert. You won’t find cell service or any other connection to the outside world anywhere in the seven-square-mile camp. But there’s at least one way to…