Capture part of screen in Ubuntu
I used to capture the entire screen by pressing Printscreen button which (launches ?whatsoever? program) and saves the entire image into my home folder. After that I used to crop it with gimp.I just discovered import command which can be invoked from command line and
modifies your cursor to cross so you can define and later save any rectangular area.
$ import save_to_this_file_any_rectangular_part_of_screen.png
It saves me time for launching gimp, so few seconds at least.