I just got back a photo album I made on Mypublisher.com that we are going to use as our guestbook, and I love it! The cover is very nice and has a picture of us on it, the paper is great, and the photo images are very high quality. We used pictures from throughout our relationship, and guests can sign and write messages in the white space. It ended up being about $60 (incl. shipping) for an 11" x 15" 25 page album.
I think I may make parent albums with our wedding pictures when we get them back. If you don't get an album with your wedding package, you might want to check it out too!