As you travel across the country, the more places you visit, the harder it becomes to remember each and every stop on your journey. And 1/2 the fun of the travel is the time spent looking back and remembering what you've done.
Having a tangible "reminder" of each place is not only a useful memory tool but also a great ice-breaker to pull out when you meet someone new, or stop to visit someone you've known for years.
A favorite way to keep record of memories is digital photos. There are drawbacks to having CDs and DVDs. When you want to share you need to have something electronic to view them. Not always the most convenient, because as RVers, spending time outdoors with friends old and new is an important part of the experience.
There are places online where you can convert those images into books that can easily be stored, gifted, and shared. One place that I've personally used multiple times is Shutterfly.
They print a very high quality product that looks like you purchased it from a book store. Their quick book sets up layouts for you and allows you to put your quick story describing the photos on that page.
If printed material is not you way of expressing yourself, maybe souvenirs are more to your liking. Visit this fun blog (RV Roadtrips) and explore some of their "memory lane" ideas.