Same here. I haven't seen a guest's charge card or gotten a signature in years. It's all done online. I require a deposit of one night's charges when the online reservation is made, and I change the balance, if any, to the same card when they arrive.
If they call or email to make the reservation, I have Reservation Key email them a secure online payment link and they make payment that way. ResKey saves the payment info so I can charge the balance due, if any, upon arrival, without having to see them or their card.
I'm amazed how easily people calling "from the road" can receive the payment email and make payment from their phones. Mobile phones are wonderful, and the generation who can't use them competently are about to the age where they don't travel without a younger person along to handle stuff for them!