1. Wave at a baby.
2. Leave a pound in the shopping trolley.
3. Wish a telemarketer Good Luck.
4. Buy an energy-efficient light bulb.
5. If someone’s sitting on their own during a pub quiz, invite them to join your team.
6. Tidy the office kitchen.
7. Spend a few minutes leaving your house/office/school in a better state than when you arrived.
8. Give someone a lift.
9. Give a disposable camera to a group of people you see having fun.
10. Give a newspaper to a taxi driver.

(with thanks to Danny Wallace and his Karma Army)