After reading that Verizon BlackBerry phones can tether via USB using the VZAccess Manager for Mac Leopard, I thought I'd give it a shot with my Sprint 8130 - turns out it works. So now I've got it downloading faster than when it's tethered with Bluetooth. Reached 750kbps download speed via dslreports though YMMV. Anyway, here are the steps:

- Call Sprint and get PAM (phone as modem) added to your account. If you are a Blackberry Powervision user, it'll cost an additional $15 per month. Other Blackberry packages have PAM already included.

- Get VZAccess Manager from here, and choose OS 10.5, USB Cards, then the USB720. When asked for a phone number just plug in the example they have circled on the right.

- Download and install taking all the defaults and then reboot. After restarting, VZAccess Manager will prompt you to plug in your phone (do so) to try and detect it. Continue with the installation and it will create a new Network Location called NationalAccess - BroadbandAccess.

- After the installation is complete, close out of VZAccess Manager. Go to your Mac's System Preferences and click on the Network icon.

- Click on the Location drop down and choose the new NationalAccess, etc. profile. Select the Advanced button and change the Vendor to Sprint, select PCS Vision for the model. Click on the PPP tab and select the Settings dropdown and choose Configuration. Make sure that Send PPP echo packets is not checked and click on OK.

- Back at the Location screen, make sure the Account Name and Password fields are blank. Telephone No. should be #777. Click on the Apply button to save changes. Close out of System Preferences.

- Now start the VZAccess Manager application from either the desktop or applications folder. It will detect your phone and you just need to click on the Connect WWAN button. If you ever unplug the phone and then can't detect it again when you plug back in, select the Refresh command from the VZAccess Manager menu to re-detect.

That's it. Good luck!

PS - Originally I thought I could just snag the modem scripts from the installation. Turns out you *must* run the access manager to connect as it interfaces your Blackberry with the OS. For some reason if you try to manually set up the interface and scripts, it works one time and then loses connection when you unplug your Blackberry.

Well done, daver42.
Definitely deserves to be stickied.