ROKCET SCIENTIST  I think 'Lock My Mac' (http://www.freemacware.com/lock-my-mac) is excellent, simple, and convenient.

Thanks, developer(s).

I hope the next version allows us users to preset a screenshot or screensaver, whereby one tap on the space bar conjures up a LogIn window waiting 60 seconds for the LogIn password or fade again – while recording a QuickTime movie of the person trying to LogIn . . .

Those little QuickTime movies to be automatically destroyed after 2x 24 hours, in accordance with the laws on privacy. So no harm done if no attempts are made.

Now THAT would make for a killer app! Security like a bank!  (Version 1.0)

COOLFACTOR  Two 3rd-party applications that use the Apple-designed FileVault icon. Good way confuse end users.  (Version 1.0)

CMILLER  I thought I would post and explain why someone would want to create this application:

My motivation for creating the application was that OS X does not have a feature to lock the OS like Windows (Windows Key + L) or Linux have. As such, I wanted to create the most focused, down the point application: that is, one that just locks OS X when launched and that's it.

I know of a number of other mac users that expressed the same concern, and so I decided to figure out a solution, and it turned out to be Lock My Mac. I spent some time browsing the web to find an app, but none were tailored to do exactly what I wanted: search for "lock" in spotlight/quicksilver, press enter, and have OS X instantly locked so I could walk away from my computer.

Hope this detailed response has satisfied anybody's question as to why this application exists.  (Version 1.0)

WIZZARD1  I use Utility Lock and this looks like an exact copy of this, even down to the icon.

As well you can not get to developer web site as there are no active links to it.

Stick with Utility Lock and if you use it before of overwritting it with Lock My Mac   (Version 1.0)