+1 on password protected Excel. I keep it updated and a hard copy in the safe with my guns in a document fireproof box (think Sentry) with all my other important papers. Every time I buy, sell, or modify a gun, I update the spreadsheet on the PC, then print a new hard copy. Like Darrell, it's not so much for me as it is to help my family in the event of my demise. The hard part is getting started, but once you have everything down, maintenance is easy. A second benefit is having documentation for insurance purposes, especially if you keep a digital copy in the cloud somewhere (i.e. Dropbox.) What I need to do now is take pictures of each to add to the documentation.