Our favourite feature of this week's iPhone update, iOS 4.3, is the personal hotspot. It lets you share your iPhone's 3G data connection over Wi-Fi with your other gadgets. That means, for example, you can tether your Wi-Fi-only iPad to your iPhone to get connected.
But how much is this little treat going to cost you? That's where we come in. Here's a breakdown, in order of awesomeness.
Three gets a tip of the hat for including tethering in your phone tariff, rather than using it as an excuse to charge you again. Not only that, Three's One Plan includes all you can eat data for plans costing more than £35 a month.
Tethering? Check. Unlimited data? Check. Sounds like the perfect hotspot plan to us, as long as you get good coverage on Three in your area.
O2O2 has updated its deals to include the use of the personal hotspot feature and tethering over USB and Bluetooth. That means you'll be able to use your data allowance however you want, for tethering or for surfing on your phone.
We salute O2 for this change, since it means you won't have to pay for two data bundles -- one for your phone, and one for tethering. After you've selected which model and contract you want, you choose a tariff for calls and texts, and then pick a data allowance. The Basics deal costs £3 per month and gives you 100MB of data, the All Rounder gives 500MB for £6, and The Works costs £10 for 1GB of data. The last two both include unlimited access to O2's network of Wi-Fi hotspots.
Unlike Vodafone (see below), you won't be charged automatically if you go over your allotment. But your data speed will drop to almost nothing until you buy more data.
We've heard from readers on T-Mobile who've been using the iPhone personal hotspot on their phone's data plans without additional costs, but it seems the party is over.
T-Mobile announced on 15 March that if you're on a contract, you can buy a mobile broadband booster that costs £5.10 per month on top of your phone's data plan. If you don't have any data included in your contract, the price of the booster goes up to £10.21. The booster has a 1GB fair-use policy.
If you're on pay as you go, or on contract but without a mobile broadband booster, T-Mo is charging the same as how it charges for mobile broadband. That starts at £2 per day with a 250MB fair use policy, £7 for seven days and 500MB, or £15 for 30 days and 1GB.
Orange will charge the same amount for the personal hotspot as it already did for tethering the phone over USB or Bluetooth. You can buy a tethering bundle starting at £5.10 a month for 500MB and topping out at £25.54 for 10GB. (Again, it's an add-on once you've chosen your contract.)
If you use more than your inclusive allowance, you'll be charged 5p per megabyte extra.
You have to be on contract to use the personal hotspot on Vodafone, so pay as you go customers are out of luck.
In a forum post, Vodafone confirmed it will charge the same amount for the personal hotspot as it already did for tethering the phone over USB or Bluetooth. That's £5 for 500MB, which expires after 30 days.
And keep your wits about you, because there's no message warning you that when you connect, you'll be getting a bill. As soon as you tether, you're down £5.
You can also invest in a bundle every month, rather than paying a fiver on an ad hoc basis. It's £10 per month for 1.5GB or £15 for 3GB. If you go over your limit, you guessed it: it's £5 for an extra 500MB.
Sadly, our favourite bonkers crowdsourced mobile phone network with unlimited data doesn't support tethering. Boo!
One more thing...
If you switch to a phone running Google's Android operating system, you can tether right now on any network. It's free, easy, and we've done it lots. Just saying.
Update: We updated the T-Mobile section on 15 March to reflect its latest prices.
Update 2: We updated the O2 section on 4 April to include its new deals.