Some time we need to record screen activity in video, there are many option in windows but on Ubuntu I found one cool command line utility that can record your screen activity.
Tool is "recordmydesktop", there is also GUI version of it but I found it quite limited in capability. Like I can not record some portion on particular windows. Using this command line tool I can do so and there are quite other interesting feature as well.
To install this tool use "sudo apt-get install recordmydesktop" on command line.
And to start recording particular portion of you desktop, you can use following command.
"recordmydesktop -x 700 -y 180 --width 720 --height 400"
This command will start recording your screen activity, to stop just press CTRL + C on command prompt and it will save recorded video on out.ogv file in current directory.