Pigment + GTK == Live effects on HD videos
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."