There is a cool tool that lets you share your nice jk2 moments with others with few clicks. It's Demo Renderer: http://www.igmdb.org/?page=render
That tool works simple: you upload your jk2 demo and the tool outputs it as an uploaded to YouTube video. All the videos could be found on "Gaming Movie Database JK
" channel: http://www.youtube.com/user/GamingMovieDbJK/videos
. Optionally you can also download the video in HQ as MP4 file.
Also there is a big DB of gaming movies on that site and feel free to contribute your jk2 frag videos there.
P.S.: this post is the same as on r2o forum, so don't wonder why you could have a deja vu feeling.