If I were to be told that I only had an hour to live I would write down my usernames and passwords to some important sites and send a delayed email to my most trusted friend so that he can send one last update on my behalf to all my contacts. I would also leave instructions about a few special messages to be passed on to a few people. He/she will be executor my my last will and this will be the last time I will trouble him or her.
I would not spend the entire 60 minutes for that. I would need some time for the final preparation.
In case the final hour was the final hour of the human civilization, then I would not bother about a last will. I would go straight to the final preparation.
The last precious moments will not be spend saying good-bye. I would like to sit alone and think of those special people who made difference to my life. The people I love the most. I would also like to balance the checkbook of my life one last time. See what I had achieved and what price I paid for that.
I wish I was strong enough to say one last goodbye to my loved ones, but I have a very beautiful picture of them in my mind where they are happy and that is how I would like to see them in the end. And such a moment requires a music like this.