But then the virus would have to just wait longer until you type your password. I favor a "secure keypad" that you input your password via mouse clicks. Next question is how to trick viruses that may take screenshots?
Make the layout of the keyboard different each time, so if the SS it, they cant auto click it in again based on its presumed location.
Hmm, what if the layout changed every 5 seconds or some predetermined time. It would make it a pain in the ass to input your password but hey it's worth it.