Well, this is my first post, as I just own the n770, but have to put it back in the shop, but will get it back soon(hopefully). I also plan on getting a data plan on my cell phone. Currently I have a Nokia 6620 w/ Cingular and no data plan. I do have some knowledge of how the internet work. But I can't seem to understand how would the carrier know if you tether your data or not. My Nokia 6620 is happened to be s60, aka symbian linux phone. So, if they just exam the packet, there is absolutely no way they would know if the data was requested from my 6620 or 770. Can somebody tell me how this work?