Alma 5:58

58 For the names of the righteous shall be written in the book of life, and unto them will I grant an inheritance at my right hand. And now, my brethren, what have ye to say against this? I say unto you, if ye speak against it, it matters not, for the word of God must be fulfilled.

I'm not sure, of course, but I do believe, and like to imagine, an actual book. And an actual pen. And an actual hand, writing our names in The Book of Life.

That's a nice thought to ponder.

(And I bet it's really nice handwriting! :))