Activity for Anonymous

I am looking for a fun/ creative way to do a guest book. I have seen the thumbprint tree and thought that was cute, but I am wondering what some of your creative ideas are!

Ok so I bit off a bit more than I could chew with all of the diy's I planned etc. We decided to ditch the plans I had for the guestbook. So now I need suggestions for a guestbook with minimum effort by us. We do not want the guestbook that everyone...