The "Touche"

Tourist + Douche = Touche

Examples:
Utilizing the local lingo or accent when you are not a local.
Wearing the t-shirt of the place you are visiting, this also includes Hawaiian shirts when in Hawaii.
Fanny pack and/or socks with sandals wearer.
OR this guy:

Jeff, just because you saw a cool surfer guy wave this hand signal out at you after he let us merge does NOT mean that you can use it at your whim.  1) you are not from Hawaii. 2) you are not a surfer 3) you are the whitest (or reddest?) person on the island.  Please stop being a touche.

Just kidding, love you Jeff, I think it is cute when you keep waving this hand signal out the window at people.