Many thanks to the OP! This worked wonderfully for me over BT and USB. For it to work over BT all I had to do was toggle it on (let it do its thing and reset) pair my netbook (running Win7) to the Phone and then join the computer to the BT PAN network of the Pre and I was golden. I did an initial speedtest through Speakeasy's Washington D.C. servers and got 1.8Mbits on the first run!
One thing I noticed is that all data services on the phone go dormant while the internet connection is being routed towards the tethered computer, so you won't be getting any notifications from pushed e-mails, nor will you be able to listen to Pandora while you use your phone tethered. Once you are done using the internet connection on your computer just toggle it off and your e-mail will begin pushing again.
I don't remember if this happened with my Touch Diamond as well but it doesn't bother me, I usually only Tether to attend emergency service calls where I have to login remotely to a server or router to do the service if I'm on the road.
Many thanks again, this made it much simpler than any of the other solutions out there and for me its perfect just the way it is. The only thing I'd change is the Apps name from "My Tether" to "Tethering" and change the icon for it to resemble the icons that represent WebOS's preference Apps with the gray diamond under it, making it seem like just another preference App, that would make it 100% perfect for me.