Traditional conventional brides do not have to have traditional conventional guest books. Certainly you can buy a standard guest book and ask your guests to sign it, but there are so a good many more guest book-like pursuits that are more unique.
Let's move from the popular to the less famous. One hot alternative allows guests to sign an image of the bride and groom. Simply take an image of the bride and groom and have it matted in a mat several times bigger than the photo itself. Place a frame around this, but don't include the glass or Plexiglas frame. You'll include this later. Some people prefer to use "bulldog" clips to keep the mat together rather than putting the picture in the frame. The picture can be framed after the wedding ceremony.
Most couples pick out a nice photo of themselves for this picture/guestbook option, although if there's a formal engagement photo, this is a superb way to preserve that photo and show it off to family and friends. If photos are taken before the wedding with the bride and bridegroom in their wedding attire, you can for certain make use of this photo. Many couples decide to either leave the mat empty or they place a temporary picture in the mat and add a wedding party picture later.
Be sure to possess a nice Sharpie marker handy and place the picture on either a sturdy easel or on a table where guests are sure to see it.
Another option is as opposed to providing an image of the bride and bridegroom to sign, the guests are provided with an image of themselves! Simply given a Polaroid camera and delegate someone the job of taking pictures of the guests as they reach the reception. Once the picture is dry, given a Sharpie and they can sign the picture, make a remark to the bride and bridegroom or hand draw a silly picture. It may be whatever the invitee wants it to be. This is a unique, and personal, method for guests to "sign in" at the wedding.
Whoever handles the taking of the pictures should also handle putting them in a photo album of some sort. A scrap booker might supply a special memory book with the Polaroid pictures in it, or the pictures can merely be placed in a nice album and presented later to the bride and groom.
Many guests don't give a large amount of thought to the invitee book. They whiz by the invitee book table more involved with getting their cocktail and hitting the dance floor. If this is a concern, supply a "traveling" guest book. Send each guest something either to sign or decorate prior to the wedding.
In this "traveling" guest book scenario, there are lots of options. One of the simplest is to send each guest a tiny piece of paper and ask them to write something meaningful or thoughtful for the bride and groom on it. The pieces of paper are returned prior to the wedding ceremony (to ensure a better response, provide a self-addressed stamped envelope with the paper) and can be compiled in some meaningful method for the bride and groom and given to them on their wedding.
If the invitee list is a resourceful or particularly close group, there is one other option that is even more meaningful. Again, in a scrapbook fashion, send every person a piece of paper to sign or decorate. The paper ought to be the size of a photograph album, so it could be a 6 x 6 piece of paper, an 8 x 8 piece of paper, or even 12 x 12, if the guests are up to that larger size.
In a letter that comes with the paper, the guests are instructed to build a memory page for the bride and bridegroom. They could include photos, quotes, little anecdotal stories, or combine all of these with stickers or embellishments. It's thoughtful, meaningful and personal and it's a superb way to include guests who might not be in a position to attend the wedding, but would still like to be a component of it.