Boda Náutica @Kristen - Storefront Life stark cheap and easy way to get photos from your guest over a photobooth?? perhaps
Even Better...DIY Wedding Guest Book Wedding Couple - Personalized Guestbook - Thumbprint Signature Guestbook - Any Sizes - Printable PDF Poster. $19.50, via Etsy.
Custom Couple Thumbprint Balloon, The original guestbook wedding balloon (inks available separately)