Guillaume's blog has some really cool Pigment bling that was demoed at last FOSDEM by Loïc (remember the guy trying to kiss himself with a webcam? :)).


Screencast of live transformation on HD videos within Gtk+

It demonstrates "[...] the ability of pigment to integrate with Gtk+" and to apply various effects on videos "[...] without any CPU cost, everything being done in the GPU. This is done in about 350 lines of python code, including 135 lines to construct the Gtk+ interface."