I think it's fair to say that the iPhone always comes with a premium price, but we're bemused by the fact that some networks are charging extra for using the new Personal Hotspot feature in iOS 4.3, despite a similar feature being free for Android phones.The idea sounds reasonable. You get to to turn your mobile phone into a mobile hotspot, allowing you to share some of the data you have already paid for, simply by flicking a switch on your Apple handset. Well, you can if you are with certain networks, not so others. At least, not without throwing some money their way. That's despite some of those that aren't playing ball allowing a similar feature for Android users without extra cost. It all smells rather unpleasant. So who are the good guys and who are the bad guys? TechRadar has done a quick survey of the networks.If you are with O2, it sounds like good news: 'We regularly refresh our tariffs to reflect the market and, crucially, what our customers want. We are launching our new tariffs in the next few weeks and will be announcing more details soon. We can confirm that Tethering will be included in our new data allowances. Existing customers will have options to move new tariffs, although some rules may apply.' How about you, Vodafone?Vodafone is rather less keen on the idea: 'The new IOS wireless hotspot functionality for iPhone can be accessed by Vodafone contract customers. The wireless hotspot uses a tethering APN and its use is subject to additional data charges...iPhone customers who are already using our tethering price plans will be able to use the new functionality with no further charges. Please note, tethering (and therefore the wireless hotspot functionality) is not currently available on PAYG iPhones.'So if you want to use it, you'll have to sign up to a tethering plan. Some people are claiming Vodafone has been backing down over this cost, but that probably depends on who you speak to.Better news over at Three. The network's One Plan already allows tethering, so it's an obvious one really: 'On The One Plan Three gives customers all-you-eat-data, which includes allowing them to use their phone as a modem for tethering, so customers on The One Plan are free to use the Personal Hotspot feature as they like without incurring any additional charges. Customers on other tariffs or on PAYG will have the data use from the Personal Hotspot feature deducted from their allowance as they would any other data use. The best value option in this case is to buy a mobile internet add on.'Finally, Everything Everywhere (Orange and T-Mobile) claims the Personal Hotspot uses tethering and as such, customers will have to fork out for a dedicated tethering data plan. Tesco hasn't responded, so you can presume at present, it's a 'no'.An issue now for sure, but when contracts come up for renewal, this is the kind of thing that can really hit home. Expect some movement on this when the new iPhone lands.