I frequently check to see what other sites are linking to mine. As I did that this evening, I stumbled upon a goldmine of GIS resources. The US Army maintains a huge clearinghouse of resources at www.tech.army.mil/gis/. There are four quite long pages of links to just about anything related to geography and mapping.
Under their section on geotagging, there is a link to my post about geotagging etiquette. I was actually quite flattered that the Army would find my information useful enough to link to it.