At one of my best friend's weddings this summer, guests took pictures with a polaroid, taped them in with washi tape, and wrote a note beside it! There was enough pages for each guest to have their own. It was quite fun to choose which page to my picture on and which tape to use!
What a beautiful gift for the Bride and Groom!
If this is something you or a friend would be interested in, message me or leave a comment! I can certainly find a journal cover that would match the covers of the wedding and create the perfect keepsake ^_^