My Sprint rep told me that you don't need a special plan, only the Blackberry data plan (modem uses Kbytes)....so go with the unlimited plan if you're going to use this a lot.
Here are the directions they sent me on how to get it working:
1. From the computer's traditional Internet connection, go to Sprint PCS Software: Sprint PCS Connection Manager Software from Sprint
, select the computer's operating system, and download the 'Sprint PCS Connection Manager for Phone as Modem/USB Cables. (The software and drivers can be downloaded free of charge.)
2. Double-click on the downloaded file and follow the onscreen instructions to install the Sprint PCS Connection Manager Software and drivers to the PC.
* When installing the software, in the Custom Setup window, select Install Blackberry Drivers in addition to the default selections.
3. Once the software has been fully installed, launch the Sprint PCS Connection Manager from the new desktop icon.
* The Connection Manager should appear displaying Initializing, then Connect your phone.
4. Connect the Sprint BlackBerry 7130e to the PC using the supplied USB cable.
* The Connection Manager will display Initializing, Searching for service, and then Disconnected.
5. Click Go on the Connection Manager to connect.
* The Connection Manager will display Connecting, Authenticating, and then a Welcome to the Sprint PCS Network pop-up box.
* Once the connection is established, users can launch an Internet session, check email, or do anything else he/she would do using a traditional data connection.
6. When ready to terminate the data connection, double-click on the Sprint PCS Connection Manager Icon in the system tray, and then click Stop to end the session.
7. Disconnect the USB cable from the BlackBerry 7130e and from the PC.