sure fire way to keep that from happening:
Get a U3 flash drive (I believe there are also programs for normal flash drives too), and get a password manager on it. After you have that, make your passwords completely random letters and numbers (most password managers have a built in randomizer) and store it in the manager. Once you've done that, even you can't log in without the flash drive plugged in. It works for me, and the U3 drives allow you to install other software on them too, so you can have antivirus, firefox, media players, passwords, everything you need wherever you go
**edit
PS, awesome sig, btw