A friend at work , sent me this well documented and informative article on geotagging.
He got the feeling I was hooked onto this technology after I nagged him about whether his Nokia N95 can take pictures with embedded GPS coordinates (No it can't if you're asking) as a research for my Embedding GPS coordinates and other info in JPEG images with C# post.
I recommend reading it , especially if you're into digital photography or into technologies mesh ups.
Roiy