Lex asked me tonight if I knew what fax machines were.  Apparently they mentioned one in a book he read.  I explained how they worked and that they were common in offices before we had email.  He has trouble imagining life before email. :-)  I gave him the example of sensing contracts to be signed via fax.  He then gave me the example of sending a website address, written out on paper, via fax so the other person can go to the website.  He has trouble imagining life before the internet as well!