A photo guest book - polaroid and washi tape! Get a cheap but cute polaroid camera, a blank notebook, and washi tape in your chosen colors. Have guests take photos and then leave a message underneath. Love this, but polaroid film is expensive and rare!
Here is a super clever alternative to the traditional Guest Book! Guests write their well wishes to the happy couple on these wooden blocks (similar to Jenga) then as the couple plays the game throughout the years they will be reminded