For doing a screencast in Linux, definitely use "recordmyscreen" and not "xvidcap". I tried xvidcap recently on Fedora 10 and had weird hangs all over the place. It looks like it's xcb that is causing the problem, but there's no real way to fix it.
So just
sudo yum install recordmydesktop -y
and then to record your desktop just go:
recordmydesktop
and you're done. It saves the file as ogg, which uploads to YouTube just fine.
Now I'm trying to find a good Linux video editor program. Cinelerra just takes .mov files as input, and doesn't like the .mov files that ffmpeg converts. I'm trying LiVES, but it's a little wacky, and takes forever to import video. Kino also is the suck.
We need something simple and better. Not a lot of transitions and stuff, just a simple way to make videos from multiple sources.