With the iOS 4.3 update, AT&T will finally begin offering the mobile hotspot feature on their iPhone 4 (Yup, that's not a mistake. It's limited to the iPhone 4.). Whether this was planned or a change made in order to keep up with the Verizon iPhone, it's great to know that AT&T is finally allowing for such a feature.
It turns out that this version of iOS 4.3 will limit the number of devices that can share the hotspot to three. Which is down from the five that was previously allowed with the Verizon iPhone (whether this will change how the Verizon iPhone handles hotspots isn't totally clear yet). Still, we don't imagine needing all that many people needing more than that.
Let's take a look at how to use the mobile hotspot feature with iOS 4.3
1) Go to Settings on your iPhone
2) Tap 'Personal Hotspot'
3) Under that page, turn Personal Hotspot "ON"
4) You will get an additional prompt asking if you want to Turn on wifi or go Bluetooth and USB, tap "Turn on Wi-Fi"
5) Now you can connect a wifi device to your newhotspot.
Know that you can also set a password for your hotspot, which is advised. This option is also under the "Personal Hotspot" page as "Wi-Fi Password."
Keep in mind that this is a real battery killer, so you will want to disable it when not in use and probably carry around a charger or battery case. You can also expect to pay an extra $20 a month in addition to your current data plan charges.