I think most people know that if you want to take a screenshot of your desktop, all you need to hit is CTRL + Print Screen.  But did you know if you hit ALT + Print Screen, it just takes a screenshot of the one active window?  This method makes it much easier when you get an error message that you want to include in your email to your helpdesk team and you don’t want to show every program you have currently open.

Also, if you use Firefox, I’ve found the Screengrab! plugin quite handy when you have a very long web page that you want to completely capture rather than just the visible portion on the screen.