The digital camera revolution has changed the stock photography business giving opportunity to hobbyists and low-cost but great looking stock photos to small businesses.  Sites like iStockPhoto.com and Shutterstock.com are the leaders in this category. iStockPhoto.com has over 3,500,000 photos available for purchase. According to this article in Forbes, some hobbyists are making up to $10k per month! It is an amazing business for all involved!