So you have Raspbian installed on your Raspberry Pi, maybe you've even installed Minecraft and are busy building and modding. Now you want to take a screenshot of your setup to show some friends, but how?
You use Scrot, which is short for screenshot. Clever name aside, you'll need to install Scrot on your Pi and then familiarize yourself with its commands.
To install Scrot, open LXTerminal and type: sudo apt-get install scrot
Scrot doesn't offer any sort of dedicated app such as Skitch does on a Mac. Instead all screenshots are taken using LXTerminal commands.
To immediately take a screenshot of your entire screen enter the command: scrot
Scrot saves files as a PNG in the current direct, which if you've just opened LXTerminal and started issuing commands would be in /home/pi.
Of course, there's more to Scrot than that. You can set a timer to take a screenshot at a specific time, trigger a selection tool to only capture a section of the screen or even indicate you want Scrot to capture only the currently active window.
For example, to take a screenshot of the active window with a 10 second delay, you would enter: scrot -u -d 10
The "-u" tells Scrot to capture the active window, while "-d" activates a timer with the number just after it indicating where to start the countdown.
If you don't want Scrot to save a screenshot into the current directory, you can tell it where to save it and even name the file when you give the command.
A command such as: scrot /Desktop/test.png will take a screenshot and save it to your desktop with the name "test.png."
You can view all of Scrot's commands by entering: scrot -h