Yeah, I know where to measure it. Those are the images that I will upload to you tonight. But if you'd like to try it now, take a look at the pictures I have uploaded several posts up. The chip that I have performed the VMOD on is the area where you can measure voltage. The pin at the very bottom is the VSENSE pin. Count two pins up (the middle pin) and that is where you need to place the positive lead for your multimeter. You can connect the ground lead to the ADJ/GROUND pin on the chip or to a grounded area of your case.

The easier way to measure the voltage when it is installed in the case is to look for a tiny metal grommet behind the APL1581 voltage regulator. There should be three of these grommets in that region, if my memory serves me correctly. Have your negative lead on a ground source and your positive lead on one of the pins. One should have a reading in the 1.??V range, another in the 3.??V range, and another in the 2.??V range. The one in the 2.??V range is the one for memory voltage. Default voltage on my 6600 is 2.6V. 2.8V seemed to be my max.