I agree, it's the easy way to save a screen shot to your computer.
For jpg it's [Only registered and activated users can see links. ] and for png it's [Only registered and activated users can see links. ].

Just create a bookmark in your browser with the above info and the next time you need to create a screen shot just click on that bookmark. The picture will pop up and then just right click and "save image as", the directory and name you want to save on your computer.