you all can try http://www.pixelio.de/
you have to register and after that you can download the pictures in original size
if you use them you have to give credit to pixelio.de and the photographer
and that is all.
but there must be other pages like this,
i just haven't found them
Das Licht am Ende des Tunnels kann auch ein Idiot mit einer Laterne sein
The light at the end of the tunnel, can also be an idiot with a lantern