Ever wanted to turn a hobby into, at the very least, income on the side? The answer to your dream isn't that far off with the explosion of the web.

First of all, although most all websites have a webmaster, do they have a graphic designer? Not likely, unless the webmaster also has this skill. There are, as a result, many places where webmasters will look for freelancers to do logo/banner design work.

http://www.getafreelancer.com
http://www.freelancedesigners.com
http://www.marketingtools.com

If you're more creatively inclined, there are any number of contests out there.

Digital Point
Photoshop Contest
Worth 1000
SitePoint

If you're into something a bit more tame, but still necessary, there are lots of jobs for photo retouching.

Picwash - Has a young consumer base
Glenn Feron - A little bit more professional

If you're into designing something for use by a lot of people, design high quality photoshop brushes. There are apparently people that will pay for really nice, high definition brushes. Plus, they're not too hard to make.

Lastly, there is some demand for ebook and report cover designers as most of these sellers are of a business mindset.