While writing an email, this will send the mail. This won’t save you a lot of time, but I like slamming the [Enter] key to really send the email.
If you have OneNote running its task, this will take a screen clipping. I prefer to send these to the clipboard by default so I can paste them into whichever application I’m using.
New in Windows8. Will actually take a screenshot and save it to your Pictures folder. Notice the camera shutter effect when you do it.
Will bring up the charms menu. Not that useful, but kinda nice.