We didn't want to spend a ridiculous amount of money on a book for people to sign just so we could pack it away after the wedding, so I combined a couple ideas I'd seen in bridal magazines. I typed up a copy of our vows, and had them printed. We then bought a wide white mat (about 4 inches, I think), and at the reception, people signed the mat with black Sharpie markers. After the wedding, my mom had the vows framed with this mat, and they are hanging on the wall in our hallway now. We provided sheets of blank computer paper for people to place under their arms/hands, so the signatures wouldn't get smeared.