InstantShot! is a killer OS X freeware application that takes screen shots. You might be thinking, why would you download a separate program when OS X already has a built in application to perform this very function? Well, to put it bluntly the built in program that OS X has, Grab, sucks.
InstantShot! is able to take: screen shots, shots within in a rectangle, shots with a timer, and shots in a series. With each shot you are also able to choose between saving it as a: jpeg, png, or tiff. Another great feature is that InstantShot! has a finder icon, so whenever you need a screen shot taking one is a simple as clicking on the InstantShot! icon in your finder bar, selecting what type of shot you want, and the way you want to save your shot.
Here is a quick snapshot I took with it to show the menu structure:
InstantShot! receives a perfect 5 out of 5
Get InsantShot! here