X-10 Hardware

I've seen the movies by Northrup on MSDN about X-10 hardware and it looks really interesting. I'm wondering have any of you used X-10 before? On the video he uses C# or VB to program applications to operate the C-11A(which in turn operates the X-10 hardware). If anyone has used X-10 hardware before, have you tried programming it yet? Can it be done in C/C++? What equipment did you use?

Personally I haven't done anything with it other than read about it when moments of interest pass.
http://en.wikipedia.org/wiki/X10