There are a few good places worth interesting.
First.
BLUEVERTIGO
http://www.bluevertigo.com.ar/bluevertigo.htm
"stock photos" section
Second.
PICSEARCH
http://www.picsearch.com/search.cgi?color=both&anim=no&size=800p&aui=1
search engine with image size filtering.
Thats all for now.
If i find more, maybe i will tell you.:)