Out of nowhere, I found this out. I thought I was in IPython shell and I did import cv2. A crossbar showed up. So, I moved it around for a while and then clicked. Nothing happened. I did import mftracker. Again a crossbar showed up. When I clicked, nothing happened. After few moments, I realized I was in Terminal and not in IPython shell.
After few hours, I opened my home directory and found out that there were two images named cv2 and mftracker. It just struck me. I opened the terminal and once again
$ import cv2.
A crossbar showed up. I clicked on some other window, and that window got saved as an image.
$ man import import - saves any visible window on an X server and outputs it as an image file. You can capture a single window, the entire screen, or any rectangular portion of the screen.
So, to save any visible window as an image
$ import foo.jpg
P.S. **pyOpenTLD - Python port of OpenTLD. 60% complete.