I agree with Chi-TownTx.
Even the guy who sold me the phone said that as long as you're careful with your use, the chance that verizon would notice, or care, is slim.
I used PDA net on my OG Droid for basic web surfing whenever I was at my Mom's house (no internet or wifi available), when I'm on my boat, or when I'm staying in a hotel that charges for web access (why is it that most economy hotel chains provide free web access and the pricier ones want you to pay?), I've never once had a problem or heard a peep from big red about it. That said, I was always careful with my use. Used it mostly to check e-mails, facebooking, and for some moderate web surfing. I'm not downloading music or movies or doing anything that would cause a high drain and I'm not using it to connect to the internet for hours at a time.
Just today, I connected my Bionic to my laptop via PdaNet and was able to simultaneously share the phone's 3G with my wife's i-pad via the bluetooth on the i-pad and the Bionic.
Chi-TownTx, what 3d party tethering app are you using?
Do wish I could find a wireless tethering/hotspot app that didn't require rooting the phone or send me to the "$30 pay here" page....