This is a Linux only solution to save screenshots using xfce4-screenshooter and xclip.
require 'x4ss'
x4ss = X4ss.new '/tmp/fun.png'
x4ss.capture
x4ss = X4ss.new '/tmp/fun%d.png'
x4ss.capture # saves to /tmp/fun1.png
x4ss.capture # saves to /tmp/fun2.png
xclip xfce4screenshooter screenshot image capturex4ss gem