Love it!! That's what I plan on doing too, only I was going to use a polaroid because I thought that would be a fun twist. But because I am OCD and crazy I don't want guests to put it in the book themselves, I'll want to organize and lay them out all cute after the wedding. I planned to put out a cute sign next to the camera/chalkboard and maybe get my sister to go around during cocktail hour asking people to write something. She's talkative and will probably enjoy that job. Here's the chalkboard I am going to use (it's from Michael's and isn't super sturdy but I liked the fun shape.) I actually used this in one of our engagement photos, so it'll be a nice tie-in, plus I love anything I can re-purpose!