You can hide guns in paper encyclopedias.
This is the most important piece of information you have received in this thread.
Personally (opinions are like body parts...we all have them, some are pretty ugly, etc. etc...)
My kids are 16,14, and 11. I have raised them to be EXTREMELY computer-centric with their education, having homeschooled each of them at least part of the time. Books, (and I was an English/Journalism major) are wonderful and should always be available. Encyclopedias serve 2 purposes: Info retrieval and reference. As such, an electronic interface is MUCH more efficient, and can include multimedia and weblinks.
That said, I LOVE the way mtnbkr recounted his childhood memories of the treed versions. My kids do the same thing, take a subject and run with it. They just do it electronically.
To me, this is killing two birds with one stone. They are honing their PC skills (essential in today's western society) and enlarging their understanding of the universe we live in.
I also encourage them to read books, but this is mostly bedside table, nighttime stuff.
I remember an episode of Star Trek TNG where Picard is reading a book, and someone comes in and mentions what an antiquated thing that was to do. It'll get that way at some point, and people will read from books for the sheer enjoyment of tactile feel of turning pages, smell of leatherbound books, and so forth. It's not my desire, necessarily, but it IS inevitable.
Fig