Well back in the day we didn't have smartphones. Nowadays is easy, you can put everything on your phone, numbers, dates, addresses. Back in the days, actually this was modern for our time we had this... an address-phone number file also a rolodex. You didn't need wifi for this one....We used to think we were so cool when we had this... :)
Please SHARE if you knew what it was and it you like to remember the good old days....