It’s probably time for the death of the humble phone book. Check out this visualisation (from Flickr) to see why…
Here are the quite reasonable assumptions on which this graphic was based:
 assuming 75,000,000 books delivered (source:www.saynotophonebooks.org)
 each is 30cm x 21cm x 4 cm (396.83 per cubic meter). Source: A ruler :)
 this gives around 189,000 cubic meters
 this is a cube with side 57.38m.