I'm using LR 2 now and I love it. But I want to understand EXACTLY what's going on when I edit a NEF. Apparently (please correct me if I'm wrong), LR creates an auxiliary xmp file to store all edit info and database info for a NEF. This includes everything from cropping, exposure changes, clone tool changes, keywords, meta data changes, etc... it's all in the xmp file. Question 1 - The NEF file itself is unaffected by anything I do in LR? Question 2 - As long as the xmp file is in the same folder as the NEF, any application that I use to open the NEF will automatically display it modified based on what's in the xmp (not just Adobe apps)? Question 3 - In order to "see" the original NEF, I only need to rename or move the xmp file? Question 4 - Are there any long-term down-sides to relying on the xmp file to modify the NEFs?