I'm not sure if there are any other linux users on this board but as I've seen this requested in other places with no solutions, I thought I would mention that there is now a tool to use the blackberry as a modem under linux. I'm succesfully running XmBlackberry as using my sprint 8703e as a modem on my gentoo linux based laptop. Check out xmblackberry.sourceforge.net for the project page.

Note:
I'm just a happy XmBlackberry user, I had nothing to do with the development.

Jon