Quote from murky:
I think this is a false sense of security. If someone can put a keylogger on your system, then someone can put software that logs all form inputs in your browser. I am pretty sure this can be done at multiple levels with or without the use of HTTPS.
Hmm... But not all keyloggers will log all form inputs, right?
Although it's not foolproof, it should be better than doing nothing.
Sure you should install anti-virus, firewall, anti-spyware, intrusion prevention system to protect yourself as well.