Hypercam and Camstudio are great screen recorders for the purpose you outlined in the original post.
Hypercam is a mixed bag, being smooth at some times and rough (due to frameskip which causes more problems than it fixes) at other times. You also have to pay to get (often problematic) sound support, and get rid of the garish watermark. It has this old feel to it, but it's solid.
Camstudio may be a bit jerky on any computer some times, but it's free and open source and many consider it better than Hypercam. But I'm not sure which I prefer so I personally suggest that you try both of them out and see for yourself. Camstudio has a great optional codec you can download which is called Camstudio Lossless. To post it on YouTube you need to convert it back to WMV in Windows Movie Maker, but it doesn't lower the quality that much. The codec will work in Hypercam, too, which is nice.
I can't give a full opinion on screen recorders, because my computer is simply too slow to run them. What they do is they take screenshots in a sequence, record the sound that your computer inputs and/or outputs, and splices them together when you're done.
Both Hypercam or Camstudio should be great. If not, even after tinkering with some performance settings (which is important), then you're computer is just a little slow for it. So if that's the case you might have to make a movie out of the GIF that you output from Pivot, making sure it's at a 4:3 ratio of course.
The following may not work with Pivot, but are great for most games.
No matter what some people may say, FRAPS IS NOT A SCREENRECORDER in the sense in that it works a little differently. I'm not actually sure how it works though. Perhaps someone else does? Anyway it's not important.
Whilst Hypercam and Camstudio can be used on anything at any time, Fraps can be only used on any Direct3D or OpenGL program, plus any Software rendered game as long as it's in full screen.
That said, Fraps is much better for what it DOES do. Plus it takes good screenshots and has a FPS counter and benchmarking too. Fraps is a gamer's best friend, but you have to register it to get full use of it.
Xfire is working on their own video recorder. But the video recorder is in beta and I haven't heard anything good about it, though. Considering Xfire is also another useful tool for gamers, its built in recorder should be a good competitor to Fraps.
There's Gamecam too. I have NO idea what that is, but I've seen it on Youtube before.