My most recent project, which is Phoenix, Arizona Historical Images, has really brought the idea into focus for me. I had originally just started with my family, and then since I had old Phoenix photos, I scanned those in, too. I'm a webby kind of guy, so I uploaded all of these images to websites and most recently to Google+. Then I started meeting people who had old photos of Phoenix, like the one here, and I scanned them in, too.
I visited the Sunnyslope Historical Society Museum yesterday and it just made me sad to think that all of the beautiful old photos hanging on the wall will only be seen by the people who visit, and will eventually just fade away simply because they are printed pieces of paper hanging on a wall. Unfortunately, the process of scanning would require taking the photos down, carefully removing them from the frames, then putting them all back up again. So it won't happen. And those precious images will be gone forever in a few years.
But a scanned image, like the ones I am posting on Google+, will live forever. And once you put them on the web, they can be shared and seen by anyone in the world.
If you're a techy person, here is my recommendation for scanning: 1200 ppi jpeg optimized in Photoshop. If you're not a techy person, and you have access to original photos of old Phoenix, please contact me, or better still, just grab that cardboard box where they have been sitting in the storage area of your museum and drop them off here. Believe me, those photos are priceless, even though they are worthless. On ebay you wouldn't get a dime. So this is not a way to make money, this is a way to preserve a legacy for the future.