Good news. I found the magic registry hack. With the hack, all that is needed is the original -unmodified- multi-adapter that came with the Touch Pro and a cheap ipod 3.5mm AV cable (i.e.,
http://www.amazon.com/Macally-Audio-.../dp/B000GGQ2ZU).
Simply plug your ipod AV cable into the 3.5mm port on the multi-adapter, plug the adapter in the phone, and set the following registry entry to a value of 1:
\HKLM\Software\HTC\H2W\TVOutCableIn
Immediately after it is modified, the Video Out format selection will pop-up. Select the proper format for your display/TV, and it should immediately show up on the big screen in beautiful color with perfect sound.
When you disconnect the multi-adapter, the value of the registry entry will revert to 0.
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IMPORTANT NOTE: Apparently, not all 3.5 to RCA AV cable have the same pin-out as iPod compatible cables. You must use iPod compatible AV cables or hope that you get lucky with whatever you've got lying around.
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Software Update (3/4/09):
Added a few cabs for those that don't want to search the thread. techfury90 provided EnableTVOutCab.CAB to flip the registry setting. *TVOutPopUp (OEM and cab), provided by Mylt1 and Mr. Good Cat respectively, add the TV Out Popup if your custom ROM doesn't already have it.