I have an o2 iphone, have unlocked it for t-mobile and was wondering, i am on the combi 50 with t-mobile, i have just had the internet plus add on put onto my account, but does this now mean that i can use the iphone for all features including internet, apps from apps store, email etc. for no extra charge providing i stay within the 3GB stated on fair usage policy? And also is 3GB enough to be able to use the iphone for internet? i am not someone who uses facebook or anything like that just dont want any surprises when my bills come through.