There are a lot of hobbyists, and amateurs out there who are sitting on a bucket load of talent and not doing anything with it. Whether you are a writer, photographer, graphic designer, or programmer, there is plenty of work out there for you to turn your passion into money.
Writers - The first and easiest option you have is article writing sites that pay for the articles you write, like Associated Content.com, Constant-Content.com or Helium.com. If you know anything about anything (and everyone does), you can start writing articles about it and making money off of it. You could also try making a Squidoo.com page and gradually update it, eventually making a solid informational resource for whatever you're talking about.
Photographers - Stock photography websites are the first places people go to when trying to sell their photography. Places like istockphoto.com, stock-photos.com, and fotolia.com are some of the bigger ones. The problem is these sites take a pretty significant part of your commision and often require photos to meet a large amount of criterion. A good site to give a try is gonogging.com. It's not as much a stock photo site as it is a 'digital marketplace'. You can simply put up however many photos you'd like for whatever price you decide on, and usually you'll manage to easily sell more than a few.
Programmers - The great thing about programming is that out of all of the above mentioned skills it is the most specialized and the one people are the most clueless about. The layman knows absolutely nothing about programming, so if you are a solid programmer it won't be too difficult to find some relatively simple jobs that need getting done. Of all of these options there is definitely the most jobs out there for this one. A quick look at guru.com, or rentacoder.com is really all you will need to find more than enough work.
Graphic Designers - Graphic design is a highly competitive market. There are just as many professional graphic designers as there are 14 year olds who think they're Photoshop wizs. No matter what you are, there are more than enough jobs to go around to at the very least make a supplemental income. Sites like project4hire.com or graphicdesignfreelancejobs.com are just the beginning. Just about any site that offers coding jobs will offer graphic design jobs as well. A good idea is to look for sites that could use some graphic design i.e unattractive, bad navigation. A great place to look is local business sites, which tend to be far from professional looking.
Again, for all of these if there is one general site you can go to that will jobs for all of these things at one point or another it's gonogging.com. Good luck job hunting!