I was wrong when I said you can’t tether a BlackBerry as a modem in Parallels. You can tether in Parallels, you just have to disable your PocketMac drivers first.

Move the BlackberryUSB*.kext folders out of the /System/Library/Extensions folder, restart, then you can connect to your BlackBerry in Parallels with no problem.

This is great, until there is a solution for tethering in OS X (the bounty is up to $560), at least I don’t have to reboot into BootCamp to connect in a pinch.