iLifeTouch has introduced Login HD 1.0, a new security tool for Mac OS X (10.6 and higher). It costs US$4.99 and is available worldwide through the Mac App Store in the Utilities category.
Login HD was designed to help you lock a screen and control it. You can personalize the appearance of the locked screen. A name and image can be displayed on the locked screen
Login HD offers: customizable wallpapers; message posting on the screen; four styles of clocks and weather displays; a customizable slideshow; and more. Plus you can choose locking/opening sounds and animations.