As per the title really, just what can be done to defeat key/keystroke logging when authenticating access?

I have just posted a related question ([how-to-store-and-verify-digits-chosen-at-random-from-a-pin-password](https://stackoverflow.com/questions/3388379/how-to-store-and-verify-digits-chosen-at-random-from-a-pin-password)) asking for advice for choosing random digits from a PIN/password. What other reasonably unobtrusive methods might there be?

Any and all solutions appreciated.