Taking a snapshot of your computer screen or a screen region is something I do quite often. Whether for showing students or mom where to find something on the screen, or making tutorials, it’s nice to have a fine little screenshot utility. I earlier used FastStone for this, and this being a great program, it couldn’t stay free forever. So if you can get your hands on older versions of FastStone Screen Capture utilties, do it 🙂
There are fortunately several other options, one is built right into Windows and uses the PrintScreen key. Using this however, causes the entire screen or the entire window of a program to be captured. So it works, although a bit quirky. In Vista this feature has been improved, and you can change the region when clipping.
I prefer to use the freeware utility GreenShot. It easily allows you to edit the screen capture with arrows, textboxes and ellipses. Just what you need to point out important features of the clip. You can download this free utility here: http://sourceforge.net/projects/greenshot/.
Edit: Another seemingly good utility for screenshooting (is that a verb in English?) is Screenshot Captor, found by way of Lifehacker at http://lifehacker.com/304548/take-and-annotate-screenshots-with-screenshot-captor