There are several sites where people make their own photos available. Many of them can be used without restriction. Some people want to know the end use.
Someone already mentioned Stock.Xchng
stock.xchng - the leading free stock photography site which is a good site.
Another place is TrekEarth
TrekEarth | Learning about the world through photography
For textures bry Mayang's Free textures
Mayang's Free Texture Library
asw