My 2 bits
All rides:
Wallet. With the pertinent legal papers therein.
Cell phone
Tools you used since the kickstand was last down. (within reason).
Day long rides:
Tools to remove tank.
Treks:
Tools to remove carbs, plugs, chain adjustment, and assorted spare parts. Expendables such as chain lube and plexis, Leather conditioner, spray detailer. Rule is to carry what you can.
