One of the funniest 30 Rock moments for me was Lutz doing karate and getting absolutely belted. Sadly I couldn't find this video on youtube, but I think it's in the second or third season.
For a much better representation of karate, I am very excited about this movie. The trailer looks great, and every time I watch it, I want to put on my gi and head down to the dojo for a bit of kumite (sparring). This is fairly close to the type of kumite that we practice, no headgear though. Enjoy!