Perhaps my favorite good act to do is to help people push their car when they need it. It's dumb, really, but having grown up in the south, people are just hospitable that way. It generally doesn't take much to do, it helps traffic, and at least for me, it makes me feel good about myself. Besides, it always irks me when I see someone trying to push their car out of traffic and nobody else is helping. Especially consi…
Once, my car died near an intersection; as I jumped out to push, two guys appeared out of nowhere alongside me to help push. It took about 15 seconds, and they waved off my thanks and were gone again. It was shocking how unexpectedly helpful they were... I tend to expect no help in a situation like that.
Helping somebody push a car (so long as you don't ask for payment after, or something) is hard to misinterpret, and has to completely make the recipient's day.