AT&T revamps data plans for iPhone. So what's changed?

On Wednesday, AT&T announced it would roll out a variety of new data plans for the Apple iPhone. Here's how the update affects you.

If you're an iPhone owner, perhaps you've heard the news: AT&T, the much-maligned carrier for Apple's top-selling smart phone, has rejiggered the pricing and structure of its 3G data plans. So what's changed? Well, for one, AT&T has eliminated its "unlimited" data plan, and replaced it with a tiered data plan, starting with DataPlus, which gives you 200MB of data a month for $15.

For folks who don't download a lot of large attachments – or aren't constantly browsing the Web – the DataPlus plan will likely be a hit. And according to AT&T, that's a lot of users: The carrier says that 65 percent of its smart phone customers sip less than 200MB a month. On the off chance that you purchase the DataPlus plan and go over the limit, you can tack on an extra 200MB for another 15 bucks.

The next step up the rung is the DataPro plan. At this price point – $25 a month – you get 2GB a data. We're guessing that most people don't regularly download 2GB to their iPhones, but if for some reason you want to download some majorly heavy stuff, you can purchase additional data, at $10 per GB. (AT&T says 98 percent of their smart phone customers don't go over 2GB a month.)

Generally speaking, the revamped data plans will be very good for light data consumers and very, very costly for the rare users who are regularly downloading a ton of data. You can change to this new system without a contract extension, but if you don't change, you stay locked into your current contract. (The old plan offered unlimited data for $29.99.)

AT&T has also released a new tethering plan, and here's where things get complicated. To tether – for those out of the loop – is to use your smart phone as a modem for your laptop. So if you're in a place with 3G reception and not Wi-Fi, you'll be able to flick on your iPhone, and get onto the Web. Under AT&T's new rubric, the tethering plan costs $20, and is only available with the DataPro plan (another $25).

Tethering, in other words, will cost you $45 a month. Crucially, the tethering plan does not give you extra data. Why is this important? Simple: Tethering can suck up a lot of megabytes. Unsurprisingly, some are furious at AT&T. Here's Matt Buchanan at Gizmodo:

Tethering for the iPhone is here, finally! Hurray! Right? Wrong. First, consider that the old, non-iPhone tethering option offered you 5GB of tethering data for an extra $30 a month. The new plan charges you $20 extra to use the same 2GB pool of data for tethering. You are not buying extra data. You are simply paying extra to use it for tethering. Let me repeat that: AT&T is charging you an additional twenty dollars a month based purely on how you use your data.

What do you think of the new AT&T iPhone plans? Use the comments section. Just try to be polite.