These ideas play up your locale. Each uses a custom rubber stamp; you can have one made at an office-supply store.
Trace Your State
Type details in four quadrants of a page. Print out (with printer set to 'landscape' mode) on 8 1/2-by-11-inch card stock; cut into quarters. Find a picture of the state (or country) where you're having the wedding; reduce or enlarge on a photocopier, and cut out. Trace onto back of each postcard with colored pencil. Stamp or write, "You are here" and an arrow.
Attach wallet-size maps to blank cards stamped with a message. With a utility knife, cut a pair of slits in opposite corners; slip maps in place.
Send word on a paper airplane, just as in school. Stamp details on the wing. Mail inside business-size envelope.