Check ITT first.
Can I use my phone to tether? PAM is NOT available with SERO (Although some people fly under the Radar with Tethering for free with a Samsung disable DUN). A few phones can indeed tether undetected. Some of the smart phones (like the Palm 700wx/p) can tether after downloading some simple software found HERE. Other phones such as the a900m can do the same with a simple hack. Instructions on how to tether with your PPC6700 are found HERE. A hack for the 700p/755p can be found HERE(advanced user hack!).