Originally from Shreveport, Louisiana, I lived in a Northern Mississippi suburb of the Memphis, Tennessee metropolitan area for several years before moving to Ohio. I am employed in Information Systems in the Cincinnati central business district (downtown.)
My favorite postcards are city skylines, or some unique sight that is native to your town or city. To my Finnish friends, I really like Kaj Stenvall cards if you have one.
Other favorites include the following:
Trains, planes, and automobiles
Monuments and statues
City skylines and skyscrapers
Churches, Synagogues, Mosques
Ships, boats, and water sports
I would love to know your favorite word. Mine is "lagniappe" --- which means a little something extra. It is a Louisiana word of French, Spanish, and Creole origin.
Tourist cards are great.