The Rand McNally fabMap is a great idea--printing travel maps of popular destinations on microfiber polyester. Everyone can always use another scarf, bandanna, hankerchief, napkin, etc, and when you're traveling in these charge-ya-for-every-extra-kilo days, having gear that fulfills two purposes ("it's a dessert topping and an axle grease!") makes a lot of sense.
But like many Cool Things, it's not a new idea at all.
The British military used to print Escape and Evasion maps for pilots who might find themselves downed in unfamiliar locales--like Iraq:
Made of silk, one of the original "miracle fibers", these maps could keep a flyboy warm in the cockpit and get him to safety after ditching in the desert.
Rand McNally sells fabMaps for San Francisco, Beverly Hills, Miami, and other US locations but I haven't seen any for truly fashionable locales like Milan or Paris. I could see a GQ type wearing one of these as a pocket square in his Lanvin suit jacket.