For many people, the process of taking photographs of people, objects, and nature is a wonderful way to spend an afternoon. Perhaps you've already invested in some photography equipment and maybe you've even dreamed of doing it professionally, but have never been able to turn that corner.
This is a perfect situation for stock photography. Simply take interesting photos and then upload them to a stock photography site like iStockPhoto. They'll take care of the rest. Over time, some of your images will be sold and used in publications and in other places and when that happens you'll earn a bit of income.
There are many, many services for this online Shutterstock. BigStockPhoto. and so on. Almost all of them have arrangements for photographers to sell their images.
If you think a fun afternoon is taking hundreds of photographs and finding two or three that are gems, this is a great way to translate that fun into an income stream.