After all the help I've received here, I thought I'd pass along what got me going for the sake of those who are just beginning the search themselves.

First, follow the steps found here -

http://www.ging.co.nz/youtube.php

Then, download v1.2.1a of Independence here -

http://code.google.com/p/independence/

Using this new version, first deactivate your iPhone, then reactivate it.

Reboot the iPhone, and YouTube should be working. It did the trick for me! Good luck!