This application is great for those of you , who wants to save memory and battery instead of using some heavy stuff with same mission.

change's log
V1.6 2009-09-11
Phone doesnt lock if there is a call in progress
V1.5 2009-08-26
1) Added an option to lock the device when a player (HTC player, WM Player, HTC FM Radio, etc) turns the screen off...
V1.4 2009-08-14 1) Added command argument. "lock". this will lock the device
2) Added a link called "Lock Now" to lock now....
3) All the links are located in a folder called "Lock Device". (because there are 4 links and I dont want to fill the directory windowsstart menu (in your language) with many links V1.3 2009-08-04
1) Commands support. The program LockDeviceGUI.exe supports 4 commands.