You could hang pictures of pictures from your trip on the location. Not sure how it would look on a neutral-colored wall, but the idea is great. You could probably spray paint the cork and get a cool effect.
Flea markets and thrift stores are overflowing with discarded china. Add a custom stencil, like numbers or a monogram, and hang to create unique wall art on the cheap. Get the floral china wall art how-to from HGTV Magazine.
DIY travel board-- love this ides. keep track of where you've gone and where you want to go. What a great idea, I think my kids would enjoy keeping up with where they have been. Would love to make it a world map.