As a travel-light person, what I lack in travel mementos, I make up for with a sketchbook full of collages, drawings, and notes. While in Copenhagen and Amsterdam I used up 4 glue-sticks and filled my 5"X7" sketchbook. Wherever we go, I find free magazines, brochures, posters, and other ephemera that I collage with in the hotel rooms. Since I can't travel with scissors (remember, we don't check luggage), I borrow a pair from the front desk for the duration of our stay.
My travel sketchbooks are the best way to capture a place and time. One day I'd like to give myself enough time to incorporate a selection of the photographs that my husband and I take while away, while the trip is still fresh in my memory. This rarely happens because once I'm back home, I hit the ground running to meet my studio obligations.