Using Creative Commons Imagery
More and more people are coming to accept the "less text, more imagery" philosophy of presenting information, but finding quality imagery remains a challenge--often a financial one.
Below, I've listed a number of pay and free sites for imagery, but lately I've been seeking out imagery available under Creative Commons licenses. Wikipedia can give you a good definition, but in a nutshell, CC imagery is put up on the web by amateur and (sometimes) professional photographers with varying usage licenses that most often allow anyone to use the image if accompanied by attribution and prohibits commercial usage (they just don't want you making money off their work.)
Flickr and Compfight are the two places I generally go to find CC imagery. On Flickr, you'll want to do an advanced search and filter for only CC imagery. When you find an image that is CC, it will be accompanied by various symbols indicating the level of usage allowed. Usually, all you have to do is give attribution by listing the image URL or the photographer's name. I generally place this information on the image hidden in a corner as much as possible.
Yes, you're going to find a lot of amateur, poor photography in the CC pool, but I'm continually surprised at the quality of some of the photography, and if you look hard enough (especially on Compfight), I think you'll find some gems, including highly specific pics from events and the like.
Here are a few slides from a recent presentation we created here using mostly CC imagery. Note that this was a print/e-mail deck, hence the small type.
Where to Find Imagery
Royalty-free and Rights-Managed
Getty Images (the biggie)
Corbis (the other biggie)
iStockPhoto (one of the best cheaper sites)
Jupiter Images (also has a subscription-option)
Dreamstime (cheap)
Fotolia (cheap)
Photocase (cheap)
StockXpert (good and cheap)
Subscription-based Services
Creative Express (Getty's subscription service)
Photoshop Tutorials list of free photo sites
Search Aggregators
Punchstock