Our site, http://www.allourstock.com is not spammy, it’s built around a nice, easy-to-use functional layout with easy drag-and-drop interface, and has a lot more planned for the future. Currently we have about 500 images but we have a database of over 7000 yet to be added and growing everyday. I personally shoot photos myself and create custom designs as well. All are available for person OR commercial use, most of which do not require attribution.

check us out on twitter as well, http://www.twitter.com/AllOurStock

Some of the sites mentioned in the comments:

Morguefile – NOT copyright-free actually, but a very permissive license, so I’m pretty sure I can use their stock. Allows commercial use, no crediting required. Looks like I might be using Freerange and Morguefile.

Photovaco – minimal info on their site, basically just this from their front page:

We provide free stock photos with high resolution for both personal and commercial projects. You can use our free photos in websites, video, TV production, forum, blogs, school projects and print medias including newspapers, magazine, books, CD covers. OK, let’s say, you can download, edit and use all photos anywhere and anyhow you like except for abuse.

Fotolia – as original poster said, you have to pay. Yes, the prices are probably reasonable for many people, but I would have to pay out of my own pocket, which rules it out for me.

Some comments upon further investigation of these sites.

Freerange – NOT copyright-free actually, but a very permissive license, so I’m pretty sure I can use their stock. From their license page:

License Summary: You can do nearly anything with the images, commercial or not. Just don’t redistribute them – this means don’t host the images or repackage them, just post a link and let others download them, just as you did.

{i.e. you can’t make your own clone of freerange, imo}

Stockvault – NOT copyright-free actually, CC BY-NC-SA license. Poison for my situation: no commercial use (e.g. private university that charges tuition), viral Share Alike clause.

Freedigitalphotos – NOT copyright-free actually, but a fairly permissive license, so I can use their stock if I provide a credit and hyperlink to their website.

Stock.xchng – NOT copyright-free actually, but with somewhat permissive licenses. I’ve used their stuff before, thinking all I had to do was credit Stock.xchng. But upon further research it seems a little more complicated than that. First, photos are covered by a variety of restrictions; most of them are “Standard restrictions”, which are the ones I used. But some have more restrictions: be careful.
Secondly, the usage summary seems to indicate I have to credit each individual artist (not the site) AND notify them too. That would a *real* pain for me.

Flickr CC content – NOT copyright-free actually, but with a variety of Creative Commons licenses. Of the 5 licenses there, the ony one I’m sure I can use is the CC Attribution License (BY). And that requires me to credit each individual artist per their requirements. A pain.

In short, none of these sites are offering truly copyright-free photos (i.e. public domain). But they all offer copyrighted photos with a license allowing some re-use if you comply with certain conditions.
For me, the “free-est” is Freerange (commercial use, no crediting required) and I think I’ll be using it in future.
Next comes Freedigitalphoto, which requires a credit & link just to the site.
Flickr & stock.xchng offer some possibilities but frankly the requirement to credit each individual artist (or even notify them!) means I won’t bother.
And Stockvault is out of the question for me: not only no commerical use, but also the viral “Share Alike” factor that means the exercises I make that include such a photo also become CC BY-NC-SA. My employers would not be happy with that!

Please note I’m not an expert, so my understanding may be wrong. And please note that I have specific needs; yours may differ, so a license that’s bad for me might be good for you.

http://www.photovaco.com

All photos are high resolution and absolutely free to use for both personal and commercial projects.