Launching apps for data files (Windows)

[Jeffrey Kunce]

Is there a standard way of launching the default windows 
app from python for a given data file (assuming a registered 
extension, etc.)?

I've been using varieties of:
    os.system('start "c:\\scratch\\test.html"')
but it doesn't seem to be very robust.

I'm guessing there are several ways to do this.
  -open application by registered extension
  -open in "default web browser"
  -open with "default mail program"
  -etc??

Thanks for any pointers.

  --Jeff