Now you've captured my interest. How do you propose to do this?

(also, there are winamp plugins that allow you to interface buttons to
one
or both serial ports if you're up for the soldering)

Well in theory I just need an extra long cable on the
headphone/microphone which will be connected to the laptop of course.
I simply have to train it to my voice and I tell it to "go to program
name." I'll have to relearn the commands. I have an old version of
ViaVoice that should work just fine.

I'm more interested in knowing about the software itself. Does it work
well? And how would you integrate it to your mp3, etc?

My laptop doesn't have any serial ports only USB.

Thereare usb remotes as well, and usb-serial converters.