Stock photos are essential in web and graphic design and many has eyed the photo stocks as an way to make profit, Bill Gates - just to mention one. The result is a huge number stock photo agencies with varying quality and pricing standards. As an alternative to the established stock photo industry there are many websites with free high quality stock photos. Recently I found this list of websites that offers free stock photos for download.

Stock Exchange (highly recommended)
Morguefile (highly recommended)
Image After
Free Photos Bank
OpenPhoto
BigFoto
USDA
NASA
NOAA
NPS
Earth from Space
FWS1
FWS2
Picture Station
Geek Philosopher
Free Images
Pixel Perfect Digital
FreeFoto
Image Base
Cepolina
Amazing Textures
Texture Warehouse
PDPhoto
Image Blowout
Piotrpix
Mandragora
Fotogenica
Mayang
Free Photo Station
Cromavista
Afflict
Creativity 103
The Photo Repository
Aarin Free Photo
Stockvault
Designpacks
Unprofound
Four Bees
Insect Images
Free media Goo
Burning Well
A digital Dreamer
Freestockphotos.com
Freewebpics
Lightmatter
Majestic Imagery
Triparalbum
Demny Onink
Twice Pix
AboutPixel
Woophy
Pixelquelle
Litetek
PIX
tOfz
Fontplay
Orangetrash
ArtFavor
ImageTemple

LogoDesignweb
Fotodatebank
Bajstock
Pixelbag
NWYH Stock Images
PhotoCase
NPS Digital Image Index
Gimp-Savy
DeviantArt Yotophoto Free photos search engine
Flickr art.gnome.org (Thanks to Pedro)

Please leave a comment if you know other great free stock photo sites with free photos and images for free download.