"Snapping a quick screenshot is a capability you get out of the box with most current Linux distributions. Hit the Print Screen function key, and you should see a dialog box pop up with a capture of your entire screen. For GNOME users this typically launches gnome-screenshot while Kde will bring up Ksnapshot. Both tools are similar in functionality and get the basic job accomplished.
"Shutter brings a full range of functionality to the screen grab process. Look under the covers, and you'll find Shutter is written in Perl and uses Gtk for all graphical functions. That means it integrates nicely with the GNOME desktop including taking over the Print Screen button. It will work as a standalone application in other desktop environments but won't integrate quite as nicely.
"Defaults
"If you want to make Shutter the default application attached to the Print Screen key, simply open the Preferences item from the Edit menu. From there select the Behavior tab and then check the Gnome-Keybinding boxes for Capture and Capture with selection. You can choose between selecting the current window and selecting a region for the default behavior when pressing Alt-Print Screen."
