Free maps from visitor centers and other travel locations make great wall hangings in new homes, or in any place you might be temporarily hanging your hat. Maps are attractive, often colorful, and always useful. They make a point of interest in a room, and offer a way to decorate for no cost.
I just recently moved to a new town in North Carolina, and have a ton of blank wall space to fill. Since most of my belongings are a continent away (long story), I don't want or need to spend extra money on wall hangings, prints, posters or paintings. Maps fill in the gap for me in my new home.
These maps look good, and draw people to them - and cost me nothing.
I got many of the maps I'm using from my small town's little visitor center, and also at the nearby ranger station. There were maps of this state and five adjacent states, maps of national and state parks, trail maps, city maps, region maps, maps of the Appalachian Trail (a long and tall map, to be sure), maps indicating best places to go for fall colors or to see waterfalls, and maps touting other scenic and cultural attractions.
I also have stacks of maps I snatched up at AAA, the Automobile Club of America. As a member, I can get as many maps of anything in my country that I can think o: state, city, town, region and highway maps. A map of the world and a map of the country. Maps that cover camping regions. The Explorer Series of maps that indicate fun attractions to visit. Upgraded AAA memberships even hand out free maps of Europe.
If you aren't a AAA member, these maps aren't free (I think they are around $6 a map), so you'll need to find free state maps from other sources.
Visitor Centers everywhere have tons of free maps on hand, and those visitor centers just across state lines are always a good bet. You can usually find state transportation maps at any kind of visitor center, in any town visitors travel. Keep your eyes open as you drive through new towns - you can learn a lot of great places to check out if you never pass up a visitor center pitstop.
Tourist kiosks everywhere often have free maps, too. Find a tourist trap, and there will be info kiosks around, particularly on weekends and other high-tourism times.
Towns with a chamber of commerce will most certainly have maps for free.
For city and region maps, most real estate offices have freebie maps to give away. No matter where you are - whether you are visiting a place, or live there - you can express interest in that area to a real estate agent, and get a few maps to enjoy.
If you have trouble finding free maps, you can get cheap ones in the used book area at Goodwills and other thrift stores. For a quarter or 50 cents, you can buy some really interesting maps others have donated. I've found used maps of France, New Zealand, and even the Moon.
Make sure to look around at garage sales as well.
Between tourist kiosks, ranger stations, forest service offices, national parks, visitor centers, chambers of commerce, real estate offices, transportation facilities like AAA, and from used outlets like thrift stores and garage sales, you can fill as much wall space as you have, for pennies or for free.
Trade up to nicer wall decor later on down the line, or switch out your maps as you get new ones. Make theme walls - walls featuring a state, or a country, or from the far ends of the earth. Cut things up and make travel collages. Decoupage your ugly garage sale furniture with maps. Put up thumbtacks on maps with places you've been, or want to go. Get creative, be thoughtful, and enjoy some savvy new wall spaces.