Lightscreen

Lightscreen is a screenshot application that runs in the background, completely out of sight, and is activated through a keyboard shortcut. It can take screenshots of the full screen, just a part of it, or a specific window. Parameters like image quality or format (PNG, JPG, PPM, XBM, BMP, TIFF) are present in the options menu. You can also set a prefix for the screenshot filename, decide if the program icon in the system tray should be hidden when the screenshot is taken, or set up the shortcut that activates the program.