Free screen snapshot software, from tucows so it's safe. I have it on every computer now. Runs in background and even if people have java or flash images, you can save them.

http://www.tucows.com/preview/222629

Capable of capturing the whole desktop, a highlighted window, an active menu, or a fixed or free rectangular part of the screen. I use the second on their menu "any rectangular area" which is like a crop box. Then save to a folder I created Screen Snapshot.

Example: