Phonebooks

I got another phonebook dropped of at my doorstep. I wonder how many trees are cut down to make the paper that is used to compile all the phonebooks printed in the United States in a calendar year?

I cannot think of the last time I've used the phonebook. I just simply go to one of the many online searches and find what I'm looking for. I'm kinda partial to http://www.smartpages.com but I'm sure there are others.

Is the phone book obsolete?