Collect Gettysburg games and toys and sell/trade them on e-bay. This idea is just plain fun!
This could be a really fun hobby and more than having fun, you will be connecting with other Gettysburg enthusiasts. You will be learning about conventions, events, anniversaries, clubs, and associations you may not have known existed. I find that there is an exclusive community for every subject imaginable! Start buying and selling Gettysburg memorabilia and you will soon be a part of a group of people who love this National Park as much as you do!
The trick for the Gettysburg lover/collector will be to be able to part with the treasures they buy!