@vesuvius:Tethering without an approved plan, even with an unlimited plan, is a dangerous path to walk. One misstep and they will charge you full price for every bit.
I walked into the phone shop and the Salesman saw the $$ signs in front of him, and told me that I had unlimited data (when it was 500MB), I bought the phone, and after a month, they charged me a small fortune. I complained, saying they had sold me the phone deceptively.
After a couple of calls to their customer service, and them giving me short-shrift, I went and left the phone in their shop, and told them to keep it, as they had lied to me. A few calls after, their management called me and offered me unlimited data, which I had 3 years ago, and still have today.
I have come to realise that I could have had a career as a Solicitor/Lawyer had I not been a programmer.