Sorry so many ideas. Someone may have stated this already. I would do just a bunch of like 6 inch squares and use the freezer paper like suggested and try to keep a seam line. As fun as it would be to get a pic of everyone more than likely that isn't going to happen unless you have someone, that is not the real photographer snap a picture of everyone as they walk in or something. If you do a 6 inch square, I wouldn't go much smaller than you can have everyone write their wishes on it for you. My cousin did something kind of like this on his wedding. Everyone was given a piece of fancy paper at the wedding and asked to write the bride and groom a small letter and to include wishes and advice and whatever they felt important to the new married couple. You could have all these on the different colored squares and then just do a simple patch quilt from everyone's squares. If you have a lot of people attend you could have two tops instead of a backing. That way everyone could write something, kids included as they always want to be. Then I would pick a color that you haven't used. Like White. And make 2 squares quadruple the size of the other ones and put them in the center. Those 2 would be for the 2 of you to write something special to one another. Anyways there is another idea to add on to the millions of other great ones.