KeyLemon is an interesting face recognition tool which allows you to log in to your system, and some websites, simply by looking at your webcam.
This can make life very easy. If your PC has several users, for instance, KeyLemon removes the need for them to all have (and remember) their own password. Instead, everyone must first allow KeyLemon to scan their features, creating a facial model which is unique to them. And then, all they have to do is look into the PC's webcam when the system starts. KeyLemon will recognise who they are, and automatically log them into the correct user account.
The same principle applies to the built-in screen saver. If you leave your PC for a while, this will pop up and secure your system. When you come back, it'll automatically recognise you, remove the lock, and you can carry on where you left off.
And you can use the program in just the same way to log in to Facebook, Twitter or LinkedIn, though only with Firefox at the moment (the developers say they're working on adding support for other browsers).
What if KeyLemon doesn't recognise you, though? This can happen, particularly if there's a major change in lighting, but it's not a problem - if it doesn't know who you are then you can always simply enter your old user name and password, so you won't be locked out.
Please note, this trial version will allow you to boot in password-free for a maximum of 32 times. Purchasing a KeyLemon licence will of course remove this limit. While we've discussed the $29.95 Gold edition here, the Basic edition is available for only $9.95; this drops the web logins and the screen saver, but still allows you to log in to Windows with your face alone.