Wow! It looks like you will be taking on quite a project, Greg.

A couple of the things you must take into consideration is the fact that many lighthouses are in remote locations without a Post Office nearby; sometimes it is very difficult to locate a postcard of a particular light; often times people go "lighthousing" on Sundays or Holidays when a local Post Office would be closed (if you keep stamps with you, you could eliminate this problem); sometimes a Post Office can be very difficult to find and they are usually in a high traffic area of a town or city making parking difficult at times.

Most of my trips to lights are in the off-season. This makes it easier for me to take pictures of lights without large groups of people hanging around. It may just be my personal preference, but I prefer to do photography work without strangers cluttering the landscape.

I also try to squeeze in as many lights as possible during my journey. Sometimes it's hard enough to get from light to light during the daylight hours without the addition of hunting down a store that sells postcards. I have found that there aren't that many stores that carry postcards. If they do, they don't always have postcards of the various lighthouses in the area.

Perhaps your idea should be altered to reflect the possibility of a "Vacation Post Card Exchange". Many people go to the coast for vacation. There is usually more free time during vacation and most people stay in a central location which would allow for them to do exactly what you have described in your post. I know I always send postcards to my relatives from each port I visit with my boat. I always keep an ample supply of postcard postage stamps on the boat and usually the Marinas have a "out-going" mail box.

I applaud your efforts, and with a little refinement, I think you may have a winner! Count me in!

Bob