So I came up with a few ideas:
1) The photo album/book that has pictures of us in it that people can sign on blank areas and pages. (This is a great idea, especially if you want to show off your engagement photos. But like I said: I don't want pics of us in my guest book - it's about the guests!)
2) The polaroid book where a friend takes polaroids of each guest (couples/families) as they arrive or approach the guest book table and then places the polaroids in a book for guests to write a nice message to us next to it.
3) A scrapbook that my sister creates of wedding themes and leaves blank places for us to add photos of the guests later. They sign a card that has a specific question or two for them to answer and then put it on the different scrapbook pages. A friend takes a digital snapshot of them and we later print the digital images to place in the scrapbook next to the cards the guests signed. The questions would be things like * What's your best advice for the bride and groom? * How did you meet the bride and/or groom? * What is your favorite memory of the bride and/or groom? * Where did you travel from today to attend the wedding or who/what were you most looking forward to about the wedding? (I loved this idea but after talking it through with my sister, the scrapbook was going to be very expensive and HUGE for 200 guests.)
4) Another take on the scrapbook idea is having a book full of little envelopes with cards/tags for the guests to write on and insert into the envelope. KMattso over at Happily After All took on this idea as a DIY project and posted about it here.
5) I also had heard of things like the wish tree or a vase or platter that your guests can sign. (This also follows with the signature photo of the bride and groom that is then framed with a large mat for the guests to sign around).
Very sweet...I do want my guests to give me their advice and wishes. But I find that at weddings I've been to when you do this you get the same generic "Wishing you years of happiness and lots of babies!" Or "We are so glad to have been here on your special day. Can't wait to celebrate your 25th anniversary with you." Those are real nice and all, but there's not a whole lot of originality in them. I wanted something like my scrapbook idea that would actually 'direct' my guests with some specific questions that I would get personal and unique answers from them.
And then I found it! The perfect combination of everything I was looking for...stay tuned for part 3! :)