I've just switched to 3 with a sim only 600 contract and am trying to ascertain whether or not I can use the tethering feature that having a 3 sim enables? 3 seem to suggest I cannot, as it is only available on the ONE plan... but how would they know? I was hoping I could use tethering via iOS (with any usage coming our of my data allowance) as have been using MiWi previously without any additional charges obviously. They're also saying that 3 charge 10p per MB over your data limit.... does that sound correct? Do they not provide a warning once your near your limit?