The only way I was able to enable data use was to drop the phone
firmware version down to 4. Even then I was only able to connect to
the extremely slow qnc network. Here's how:

Open the service menu (press OK, 0, 000000)
Chose 3, Network Select.
Chose 4, P_REV Preference
Select MOB_P_REV4

The phone will now re-boot into a digital only mode.

Use either a cable or Bluetooth to connect with the phone as a modem.
Use the dialer to access #777
Use username: qnc
Use password: qnc

It's slow, but it's the only way I've been able to connect.

When you're done go back to the service menu and select MOB_P_REV6 to
put your phone back into the 1X/EVDO mode.