Here's a link to a site that has posted an official RIM document telling you how to use the Verizon Wireless BlackBerry 8703e (due out as early as tomorrow) as a tethered modem.

OK:

First you need to have the BroadbandAccess Connect plan from Verizon Wireless. The manual tells you to either call 1-800-2-JOIN-IN or visit your local Verizon Wireless retail store.

Now for the steps:

1. Install the software- First, make sure you have BlackBerry Desktop Manager Version 4.1 or higher. To check which version you have, open the program, click Help, then click About Desktop Manager. BlackBerry Desktop Manager Version 4.1 can be downloaded from http://www.vzam.net/blackberry.
2. Insert the VZAccess Manager CD- that came with your device and run the wizard to install VZAccess Manager on your laptop or desktop PC. VZAccess Manager can also be downloaded from http://www.vzam.net/blackberry.
3. Restart your computer-Don't you hate when they ask you to do that?
4. Connect to the network.
5. Double-click the VZAccess Manager application icon. At the prompt select Detect WWAN device, then select USB Port.
6. Connect your BlackBerry device to your computer using the USB cable that came with your device. VZAccess Manager will detect your device automatically.
7. Enter your BlackBerry device phone number then click Connect.
8. When you're finished, disconnect from the network and unplug
   your BlackBerry device.