What a nifty idea! if you want creative envelopes, go to Maps, map the route from your letter to the other person's mailbox. Print them up, fold them into 8 by 11 envelopes (or smaller if you are sending cards). This would be cool for pen pals
DIY map envelopes- make them picture (a little larger than sized, and use maps of the places you've been to store the pictures from that trip. Write place + year on front and store them in a box together. Love this idea!
Map Scrapbooks Give the maps that guided you to favorite destinations a second life as scrapbook showstoppers. The printed papers become colorful and fitting backdrops for vacation mementos. How to Make a Scrapbook with Maps
Travel Journal Love this envelope idea with map on the flap! Use this for train/California related items (train tickets and other items). Use map from Flagstaff to Fullerton possibly or California areas we will be visiting.