Update update: Just extrapolated this new definition from a Defective Yeti post about the horribly horrible X-box-game-turned-movie, Alone in The Dark:
Jar-Jar: vt. to oh-so-wrongly insert a performer or performance into a (exploitative of children? stultifyingly boring? crassly commercial? help me here) work, either through editing or the use of digital image manipulation and/or computer graphics techniques. [Jar-Jar into]
alt. To Be Jar-Jarred [Ex.: “And until I hear otherwise, I’m going to assume that Ben Kingsley was digitally Jar-Jarred into this film without his permission.”]
Also, as Wayne Bremser might say: “VW Jar-Jarred a long-since-dead and once-revered Gene Kelly into a soulless euro techno music video disguised as an endearing homage advert.”