Chalkboards are extremely trendy right now! To give your guests something sweet to read, display a relationship timeline chalkboard. If you want to make your own chalkboard, you can purchase chalkboard paint at a majority of craft stores.
I love this idea. An envelope guest book. You just take a store-bought scrapbook/album and glue envelopes into it. Lay out colored pieces of paper for guests to jot notes down on, and then they can place them in the envelopes.
Custom wedding guest book wood rustic wedding guest book album bridal shower engagement anniversary - Fingerprint Heart Totally Making this! but maybe just as decor. I want the birds in the tree with the fingerprint leaves as a guestbook