I have 2 boys, 10 and 17. My youngest does things like sweep, mop, load the dishwasher, take out the trash, feed the animals, vacuuming, and clean his bathroom (includes scrubbing the toilet). My oldest does things like mow the yard, work in the garden, take hay to the animals, or wash my car. When they do these things
without being asked, they get paid a certain amount per chore and its paid at the end of the week. They are both expected to keep their bedrooms clean with no pay. To me, that is not a chore its just something you do as being part of a household.
And as I mentioned above, they both earn money with things outside of the home like tobacco or selling eggs. That money is theirs to keep and I let them spend it how they like, but I do give guidance when they want to buy something and suggest thrifty ways for them to spend.
For those who don't live on a farm type setting and don't have all these options I would suggest (in addition to the house work I mentioned) - setting the dinner table, cleaning out the garage or shed, organizing a closet, walking the dog, cleaning the litter box.
Another thing to consider is that just because you don't live on enough land to have a garden doesn't mean you can't have fresh vegetables. Get some cheap flower pots and let your young ones plant tomatoes, squash, herbs, potato's, green beans, or carrots. You can also dig a very small place in your back yard for cucumbers, cantaloupes, watermelons, or pumpkins. Let your children tend to the entire "garden" from start to finish. When they reap the "harvest" you can buy the fresh vegetables from them instead of the store. The idea is that its more about teaching them to grow their own food than the money but doing it as a way to earn money is an incentive for them to do it. Your family ends up with fresh vegetables grown by the love of your kids. My best friend lives in the middle of DC and does this. Her kids feel so "big" about being able to contribute to the family's food supply. She lives in a town home with no yard. They do it in flower pots on her patio.