There are plenty of opportunities for the small time entrpeneur in towns, I got my unemployed and dreamless ex son in law in the past to do a deal with Tesco's and Sainsbuys by rescuing all the knicked and abandoned shoping trolleys where they could be found, hosing them down and returning them to the shops. No vehicle used, just wheel them down the road, the knackered ones sitting in the ok ones. The reason is, those trolleys retail at about £250 a go, so an obvious loss to shops. Someone else I knew also did a mobile shoping trolley repair service, fixing castors that had been bent, you know those trolleys with a mind of their own in shops, is caused by out of true castors.
Also, when I was in Denmark and low on cash, I did what a lot of the local skinties did, scour bushes and public areas for Calsberg beer bottles so I could take them back to the supermarket and get the money on them, often to buy beer, but the system works, we used to do it in this country, but now we don't and so have crap everywhere.
Me, I got my activity, it does not provide money, but provides the materials I need for my jewellery work, material that is otherwise unobtainable these days except for I believe one supplier who charges loads due to the now specialist nature of the stuff. The bi product is, I am cleaning the enviroment of discarded waste.