Rehearsal Dinner "Packets" -- Bride/groom madlibs, wedding schedule for everyone, list of phone numbers the wedding party might need the day of, etc. - I especially like the list of phone numbers idea!
Birthday or anniversary party idea - have a wine bottle guest book. Bring a special bottle to a party with silver and gold sharpies, leave the decorated bottle behind for the guest of honor. Save a wine bottle from your wedding and use at anniversary