Love the natural invites (the brown) and the idea of the fabric (or other cool paper band, like the other light pink one I tagged before). Also love the RSVP card attached with ribbon in front (and that it's online RSVPing to save paper and cost).
Message in a bottle for anniversaries. Have wedding Guests write a note(s) and they can choose what year to personalize their note for. Then they stick it in the appropriate bottle! Married couple reads the notes on the matching anniversaries.