There are certain usb keys and software out there that can be used so that in order to log in you need your specific USB plugged in, however because of the fact that you need it to log in, if you lose it or it breaks your screwed, and it only works if you log out first. That might prevent evil people from logging in, however it will not prevent them from attacking if you stay logged in or leave the key in. Another good security idea is to use a fingerprint scanner, and just make your password very cryptic, while having it so that you just swipe your finger to log in, and log out when your done. Still however, there needs to be a USB port locker of some kind, I agree.
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I got a C++ in programming...