One of the amazing advantages of the digital nature of e-books, coupled with the tiny size of storage media these days, is just how easy it is to carry around a whole library.
In The Stainless Steel Rat for President by Harry Harrison, one character’s hobby is “collecting universities”—by which the book actually means university libraries, digitized and stored. Closer to the present-day, the protagonist of Vernor Vinge’s Rainbows End is at one point given an entire millions-of-books library on a single storage chip.
Today’s xkcd taps into that same sense of wonder. (Though it is slightly non-worksafe, so you may want to wait until you get home to view it.)