I assume that the show reel will be one of those montage-set-to-music deals, so you probably won't need any audio at all. If that's the case then yeah, CamStudio should be fine. I tested it out recently and it captured video just fine, but when I tried capturing audio too it went bonkers on me.
box.net/shared/dsd43anbtd
had nothing to do so i compiled a whole bunch of my stuff for this.
You have some really cool looking stuff there Quazi, but none of it is really in any sort of finished state. It's all a bunch of tech demo stuff that is neat to play with, but I don't think it'd be that impressive as a five second clip. Out of all of that I would recommend that the evolution and the blobber demos go into the reel because they're the most polished and finished-looking. Perhaps Mr Winch, if you want to add some graphics to it (it looks like a lot of placeholders). Likewise with the IK Robot... the robot itself looks really nice but just having a robot walking on a plain black background won't look all that impressive on video.
Just my two cents. I think the reel should showcase more finished-looking things, is all.