I was a long time TREO user and had used PDANet for tethering. I checked their site recently and they now offer a BB version.
It uses your standard data plan, and is USB or Bluetooth connectable.
The TREO version was just as fast as the Verizon Air Card (had that too for a while). The current BB version 1.20 is designed for the Storm, but works with all BB devices. It seems much slower than the TREO version, and I have reported that to them. They are working on speed issues with the non-Storm devices so hopefully is gets up to par soon.
Great software and I will be using this for my tethering needs when it gets up to snuff.
Junefabrics.com is the website for PDANet.
Getting used to BlackBerry now...
I like it