Screen Capture in GNOME3

GNOME3, aka GNOME Shell, provides a comprehensive set of hot-keys for capturing images from your screen as well as recording your desktop session.  These tools are priceless for producing documentation and reporting bugs;  recording your interaction with an application is much easier than describing it.

Alt + Print Screen : Capture the current window to a file
Ctrl + Alt + Print Screen : Capture the current window to the cut/paste buffer
Shift + Print Screen : Capture a selected region of the screen to a file
Ctrl + Shift + Print Screen : Capture a selected region of the screen to the cut/paste buffer
Print Screen : Capture the entire screen to a file
Ctrl + Print Screen : Capture the entire screen to the cut/paste buffer
Ctrl + Alt + Shift + R : Toggle screencast recording on  and off.

Recorded video is in WebM format (VP8 codec, 25fps).   Videos are saved to the ~/Videos folder and image files are saved in PNG format into the ~/Pictures folder.   When screencast recording is enabled there will be a red recording indicator in the bottom right of the screen, this indicator will disappear one screencasting is toggled off again.