The Rev-matching post is pretty close to spot on. I believe I remember reading somewhere that you really aren't saving wear on the dynos unless the transmission becomes completely disengaged--which requires double-clutching. If the clutch is not let out as you pass through neutral, all you are doing is avoiding the snap as engine speed is brought in line with the road speed.
Here's a pretty decent tutorial on the technique. Definitely install the spacer to raise the accelerator, and install performance pedal covers to allow you to work both at the same time.
http://www.turnfast.com/tech_driving..._heeltoe.lasso
Cheers!