Don't leave home without it...
Riding today on Georgia's Silver Comet trail, I came across a young college student with a flat front tire. He did not have a spare tube, pump, or any tools. I offered to help change the front, very willing to give up one of my two spare tubes when his rear tire went "pop" as we were standing there. He wasn't even sitting on the bike! A ten mile hike in a steady rain with two flat tires was forthcoming. Luckily, the Sheriff's patrol in Paulding County, GA, came by about an hour later to give him a ride. In the few minutes I spent trying to help, 3 sets of people came by--- they all asked " Is everything o.k.? I said "no" each time. No one stopped, they kept on riding.