i need to ask yall a question... i have jailbroken unlocked iphone 3g 3.1.2 and i used app called sinfuliphonerepo  from cydia to tether internet. I also have unlimited data plan so past few days i am using internet excessively thru USB plugged in to my laptop... i am not sure if AT&T will find that and charge me extra for tethering on the top of my bill.. has anyone gone thru this stuffs... any ideas  would be highly appreciated.. thanx yall