At our wedding, we didn't have a guestbook. Instead, we asked our guests to write their well-wishes to us on postcards collected by close friends from the cities we love (LA, SF, TO, NYC...). Some of them have wise advice for a successful marriage written on them, some have heartfelt congratulations, and some of them are drunken nonsense... but all of them are awesome and make me smile.
A sampling of them hangs above our couch as a constant reminder of home, and all the people we love. It makes us feel connected even though we're so far away.