Locals in Beichuan county in China's Sichuan province, including children commuting daily to school, have to use a zip line to get across a river because the bridge that collapsed during the May 2008 earthquake has never been rebuilt. (via wsj)
Update: The residents of Los Pinos, Colombia use a zip line to get across a 1200-foot-deep gorge every day. Each rider brings her own pulley, rope, and piece of wood to act as a brake. (thx, noah)