My bike kit

Clockwise from upper left corner: Pump, multi-tool (including chain tool), locking skewer key, zip ties, patch kit (old fashioned kind), tire levers, adjustable wrench, sunscreen, extra chain links, bag to put it all in, and sharpie. In the middle: dollar bill and instant patches. Random notes on these items: I've never used an instant patch on a tube, but I have used them for repairing other bike accessories. The dollar bill as a sidewall patch has not worked for me (yes, I tried), but I figure it might pay for a phone call. I use the sharpie for marking up the location of holes on tires and tubes. Zip ties are about the most useful thing in the whole kit. If your chain breaks, you'll need extra links. An adjustable wrench is necessary if you ride with cheap, vintage, or cruiser style bikes. I have used everything in this kit except for the extra chain links, but I know plenty of folks who have broken chains on the road and trail. That convinces me it is worthwhile to cart them around. Besides, they're purple.