As a teenager I lost £20 in a shop. Someone handed it in and I got it back. I’m glad some of you didn’t find it!
This seems to be my year for finding money on the ground. In January I found 25 bucks when I was walking the dog, and a few weeks ago, I found a 10 dollar bill among trash and leaves outside work. I’m getting into the habit of looking down while walking.
Over the years I’ve estimated that I found somewhere around $400 in various amounts, from a buck to a couple of $20s together. I’ve had no qualms about picking it up and keeping it. If I actually saw somebody drop money (and I have) I’d pick it up and give it back to them, but if I’m just out walking along and find it, great and the same goes for anybody who’s found money I’ve lost.
When I’ve found a couple of wallets I’ve returned them.
I just recently found an opened envelope containing a check for 100-some-odd dollars on the floor of a restaurant. It was situated such that it was likely that someone sitting at that particular table had dropped it (and not, say, someone just walking by), and there had not been anyone at that table since I came in. It was made out to an individual, and drawn on the account of a church. I didn’t think to look to see if the back had been signed. I turned it into the counter staff, who called the name over the PA system, but I think the person had already gone.
I found a shiny penny at a buffet restaurant today. Pardon me while I gloat.
Smug bastard. That was MY penny. 
I can prove it. It had a picture of Lincoln on one side and the Lincoln Memorial on the other, didn’t it?
A number of posters (OK, maybe just one, I can’t be arsed to scroll up) have said that when they find money they give it to a homeless person. Is this not good enough? And what magical superpower do you think the police have, that they can find the owner of a $100 bill better than I can? Are they going to go around asking people if they lost $100? I’d imagine everyone would either get scared and run or claim it was theirs. That’s if the cop bothered to find its owner, and I don’t know about you, but I don’t trust a cop to take time away from his quota run to deliver lost cash. And the average cop doesn’t need $100 nearly as much as I do.
As for me, I can’t remember a specific example where I’ve found money. Maybe a dime every once in a while. Although Rigamarole’s example reminds me of a time I found someone’s wallet at the apartment complex I lived in. I got someone to let me into the building (the complex was split into four buildings and you couldn’t get into any of the other three with the keycard from yours) and went to the address on the card and gave it to her roommate. The roomie called the owner etc., and the owner actually said she wanted to thank me in person when she came home from work that night, but I declined and went home. Kicking myself the whole way, of course. The girl was a fine specimen (if she still looked like the picture on her driver’s license, anyway) and I realized as soon as I walked out of the door that I may have written myself out of a good story.
When I was first visiting Tokyo looking for an apartment, I found a credit card on the sidewalk. When I turned it in at a nearby police box, the officer asked, “if nobody comes to claim it, do you want it?” Uh, yeah, sure.
Karma smiled, and a year later when I stupidly left my cash card sitting on the ATM, whoever found it turned it in to the police and I got it back.
I’ve yet to find any considerable sum of money, but I did find a £5 note once. I handed it in at the police station. The officer expressed suprise that I hadn’t kept it.
For those of you who do keep the money, how do you know it isn’t fake, and what’s the penalty in your area for trying to use fake currency?
Well, I’m sure that the police DO have a better chance of finding the rightful owner than I would - there are more of them, for a start.
That aside, if I were to hand in a sum of money at a police station, describing when and where I found it, and the owner was to contact the police stating when and where they had lost it, I’m pretty sure they would be reunited with their property, so it’s not an entirely ridiculous idea to involve the police. It’s not worthwhile for trifling amounts, but for larger amounts, the owner may have reported the loss.
They don’t need to do that - they are a centralised, recognised authority, to whom (some) people already report losses and thefts.
I’ve never found much money just laying around, but it does happen sometimes. I was swimming in a lake and saw a $10 and a $1 bill in the water. My friend was right next to me and I knew I only had time to grab one of them so naturally I snatched the $10 bill. If I found money on the ground or something, unless there is some obvious way of finding the owner like an ID next to it I would just keep it.