You know the feeling. You've just come up with the most amazing picture, but it lacks a background. Or you need to spruce up a web site, and can't find any pictures to use. Then again, maybe you just love architecture, or something else, and simply want to see some nice photos.
The thing is, if you want to use a photo publically, either you take it yourself, or you spend time finding it, and spend time tracking down the rightsholder, and spend time trying to contact the rightsholder for permission, and so on ad nauseam. Or, you just find yourself some nice stock photos.
One very useful resource for stock photos is stock.XCHNG (sxc.hu). With existing categories and a very nice search function, it's easy to find relevant photos, and any usage restrictions placed by the photographer are listed conveniently below the photo. Being a submission-based site, the quality can vary, and some pictures are definitely rather amateurish, but at the other end of the spectrum, I've seen some very professionally done photographs, and the general quality is quite good. I would note that courtesy and copyright law both dictate that one honor any usage restrictions placed by the photographer.
The site does require registration, but that registration is free. It'll ask some rather specific questions, and will require that you fill in stuff like phone number and street address, but those don't necessarily have to be correct. In fact, only three pieces of information must be correct: the username you want, the password you want, and an email address. Just enter stuff that sounds okay for the rest of the info (I gave it my correct name and birthdate, but incorrect phone number and address).