Shutter is a feature-rich screenshot program. You can take a screenshot 
of a specific area, window, your whole screen, or even of a website - 
apply different effects to it, draw on it to highlight points, and then 
upload to an image hosting site, all within one window. Shutter is free, 
open-source, and licensed under GPL v3.

perl-goo-canvas is an optional dependency for editing the screenshots
directly using a built-in editor.
exiftool is an optional dependency to enable Shutter to write Metadata
(Orientation) when saving Jpeg-Files instead of simply rotating the
image.
