As a freelance software developer for Nokia phones I often find myself in the situation where the program I'm testing goes into an infinite loop (which I forgot to close because I was in a hurry ;)). If I try to close it by pressing and holding the menu key and pressing the "C" key on it, it usually doesnt' work. Then I started using Handy Taskman, a taskmanager with the ability to kill processes, and many other useful features. That made my life a lot easier.
So I made a video in which I show the application. Enjoy!