What do you think about my idea - smart NFC authentcation device?

While a lot of people are trying to solve security issues these days I cannot find a good solutions to some of the core problems. Where to store my private keys and how to access them. On the market there are some USB devices that can do the job but in my opinion they are not secure enough. Access to them is granted via PIN code typed on the computer keyboard. Intercepting the PIN code via ordinary keylogger is pretty easy task. Another problem is that you cannot see what actually the USB device is doing at the moment.And I think the best solution is standalone NFC device with keyboard and display. It can be used to automate site logins, data encryption, payments, filling web forms and a lot of other stuff while providing higher security not possible to achieve on any PC. Someone can say that a NFC smartphone can do the job but smartphones are too far away from secure devices and not very reliable.