I do a fair amount of image creation for my church web site.  So I was happy to learn about CreativeMYK.com and repository of royalty free images for church audiences.  It is a new site so it should have more to offer over time in way of images and in features (currently searching is painful)

Credit to: Joel Young

Now as an addition I also use two other sites for my sources:

www.sxc.hu - A site with user submitted images.  Licensing varies but most images are free to use.  Their search feature is pretty good.

www.creativecommons.org - This is a search site that links a few sites together and you can check a box that will limit your search to royalty free images only.  Nice way to find good photos.