Need help with pen for guest book

I have a guest book for the eparty I am using. We would like for people to write some words in the book rather than signing their names. The book will be passed around from table to table and I will have someone taking care of this for me. Except I don't want the person standing their watching the people write unless this is okay to do??

What kind of a pen can I use and how do I attach it to the book? The binding is covered but the inside of the binding is spiral. Does that make sense?

bumping.

I was thinking of placing a pen on a string. I have satin ribbon I can use for this.

I also thought of placing pens on each table but I don't really like this idea too much.