I've heard of Telecom NZ users trying to flash their Touch's by reading the tutorial and then not having any EVDO Data access afterwards.
Before doing anything you MUST get your HDR Auth Username and Password. It is unique to your phone and Telecom won't supply it again afterwards.
To do this go to the EPST menu by the following method.
"Dial pad > ##778 & green call button > EPST edit > 658824 > view info > security > NOW WRITE ALL HDR ENTRIES DOWN AND KEEP IN A SAFE PLACE!"
Once you have this info you can merrily follow the tutorial to unlock your phone, perform the flash upgrade, and then enter this HDR info back in again afterwards.
For Telecom NZ users I recommend
OMJ's Sprint Clean version.
Moderators: Any chance of making this sticky?