Issue resolved on the D620

I've only done the audio piece:

1) Moved VoodooHDA.kext, VoodooMonitor.kext and VoodooPowerMini.kext into the "Kext Utility" app icon provided in the package. Entered my password et voila... the kext's were installed properly.

2) Double clicked VoodooHDA.prefPane in order to get it installed
3) Opened System Preferences and launched the VoodooHDA icon and set the volumes up for the "Recording Level" at about 50%.
4) Went back to "show all" in system preferences and opened the SOUND icon
5) Clicked the input tab and saw there was audio coming from the internal mic!

6) Opened the VoodooHdaHelper folder provided in the pack and followed the instructions
7) Also moved the VoodooMonitor icon app into the /Applications folder

At this point I can safely say the internal mic works fine. I've also ran a test call on Skype and it sounds great.
I will later reboot the machine to see if the input audio settings "stick" the same or will have to modify every time I login. Hope it sticks tho.

Thanks
Ed

DELL Latitude D620 running MAC OS X 10.6.3 installed from retail DVD