Screencastomatic works better tha CamStudio, I feel, but the free version is watermarked (you could record a bit more and edit that out). I forget how much the Pro version is but it's probably worth it. There are other free programs, too - Google a bit and try them as what suits me may not suit you.
Djoe, I'm interested to help with the API thing if you're still looking for someone. My time's a bit limited these days, but I have already written some (private) API applications in PHP / MySQL so perhaps we can do something together.