Update - Card free ATM's are becoming a reality at one of the largest banks:
Bottom Line: Recently I shared the information that a consortium of big banks led by Bank of America, JP Morgan Chase and Wells Fargo had been working on a card-less ATM process. The process allows you to authenticate via your mobile device. This would allow for enhanced security for you and the bank (preventing card skimming at ATM's & issues with lost cards).
The update is that Wells Fargo didn't waste anytime. They've begun their nationwide roll-out to more than 13,000 ATM's nationwide. The service is already available throughout South Florida. So if you're a Wells customer - ensure your app is updated & you'll be able to try this out the next time you access a Wells Fargo ATM machine.