We see it quite frequently up here in Thunder Bay, ON. Mesaba has done a nice job on this one, or I should say two! There are actually two SAAB 340B's painted like the map you are talking about in the Mesaba Fleet. It outlines all of the destinations they served when the aircraft where painted (about a year an a half ago I think) direct from the factory.
Keep watching, you'll never know what you will see!