AT&T announced Wednesday that the company was drastically changing their data plans, including cutting its unlimited data plans completely. If you own an Apple iPhone, iPad, or another smartphone, here are the nine critical elements you need to know about the new AT&T pricing plans.

AT&T that the company was drastically changing their data plans, including . Of course, this all occurred before Apple's Worldwide Developer Conference (WWDC) on Monday, when Apple is to announced a next-generation iPhone.

While some customers are crying foul that their unlimited plans are being axed, the changes might . Since more than 90 percent of users don't use over 2 Gbytes of data per month, moving from $30 per month for unlimited data to $25 per month for a 2-GB cap could actually be a good thing.

When we studied six PCMag.com iPhone owners' data use, we found that every one of them used less than 2 GB a month. Of course, if you tether your laptop or watch video on an iPad, you might use a lot more than that. Here are answers to some common questions on the new plans.

When do the changes go into effect?

Monday, June 7.

How much do the new plans cost and what do I get with them?

There are two options for data plans and one add-on option for tethering.

Plan Option #1: DataPlus. Customers get just 200 Mbytes of data for $15 per month. Additional 200-MB blocks cost $15 each. If you use more than 200 MB a month, the DataPro plan becomes more affordable.

Plan Option #2: DataPro. Users get 2GB of data for $25 per month. Overages are billed in 1GB increments for $10 each.

Tethering: Anyone who wants to use their phone as a laptop modemincluding iPhone customers  can do so for an additional $20 per month. Keep in mind that you still have the 2GB cap and tethering will make hitting that cap a lot easier.

Can I keep the AT&T data plan I currently have?

Yes. Current AT&T customers can keep the data plan they have. As long as you don't opt-in to one of the new plans, AT&T will let you continue to use an older data plan. Once you change plans, you cannot return to an older plan.

How does this change iPad data pricing?

Previously, the iPad had a $30 per month unlimited plan. That is going away and being replaced with the DataPlus and DataPro plans. If you had the $30 per month unlimited plan before June 7, you can keep it until you don't want it anymore.

Can I tether my phone to a laptop on the new plans?

Yes, but you'll have to pay more to do it. iPhone tethering will cost $20 more a month on top of your $25 for 2GB of data. You will still be using the same data allocation for tethering.

How can I keep track of my data usage?

Customers will receive text message notifications as they hit 65 percent, 90 percent, and 100 percent of their allotted data, as well as e-mails if desired. A free myWireless app will let users check data usage.

Should I be worried about going over my 2GB data cap?

AT&T has been pointing out that 98 percent of current smartphone users consume less than 2GB per month, and 65 percent consume less than 200MB per month. But as consumers become reliant on the benefits of mobile e-mail, Web access, and so on, they do it more often.

At the PCMag offices, we how much data six employees with iPhones were using per month. We found that 200MB per month won't work for most tech-savvy smartphone users. However, we were surprised to find that all six used less than 500MB of data per month, mostly thanks to having Wi-Fi connections at work and home. Other users might have different results.

How can I cut down on my data use if I use more than 2GB per month?

Generally users would need to use more Wi-Fi, if possible. All data plans include free AT&T hotspot access over Wi-Fi.

Are other carriers going to change their data plan pricing as well?

At this point, no other carrier has said they are changing their data plans. But usually when one carrier makes changes that will improve its bottom line, all of them change in some way or another to be competitive. Concerning data plan prices, Sprint chief executive Dan Hesse recently said in an e-mail that "one can never say 'never,' but [the company] has no current plans to change our pricing."