I second this. Environment-textures is a nice alternative, although some of the images do tend to be a little bit more 'raw' compared to cg-textures. 3Dtotal also now has a free texture collection that they are building up often. http://freetextures.3dtotal.com/
Yeh cg textures is awesome :D Also try Autodesk Area, there's over a hundred there, most are very high quality. Taking your own photo's is alot harder though, you have to be in the right lighting conditions and have a very expensive camera to get the right quality otherwise they end up being for low opacity dirt and stuff…