Following in Verizon Wireless' footsteps, AT&T today unveiled new shared data plans that will let customers apply one data plan to up to 10 smartphones, tablets, and other Internet-connected devices. The plans will be available in late August and also include unlimited talk and text.

AT&T Mobile Share plans start at $85 per month for 1GB ($40) and one smartphone ($45) with unlimited text and talk. The cost per-gigabyte and per-device goes down as you upgrade your data package. For example, 4GB of data will set you back $70 a month plus $40 for each smartphone, while 6GB of data is $90 a month plus $35 per smartphone. Additional data is priced at $15 per GB out of plan.

Additionally you can include basic feature phones for $30 a month; laptops and netbooks for $20 a month; and tablets for $10 a month (full breakdown below).

First, Choose your monthly Data Amount
Mobile Share with Unlimited Talk & Text 1GB 4GB 6GB 10GB 15GB 20GB
  $40 $70 $90 $120 $160 $200
Each Smartphone: + + + + +  
  $45 $40 $35 $30 $30 $30
Additional data: $15 per GB
Next, add more devices to your plan
Basic and quick messaging phones Laptops, LaptopConnect cards and Netbooks Tablets and gaming devices
$30 each per month $20 each per month $10 each per month

AT&T's prices will closely match those of Verizon in most cases. One smartphone with 1 gigabyte of data will cost $85 per month with AT&T, compared with $90 with Verizon. AT&T charges slightly higher data fees for plans above 4GB but the cost per smartphone is lower so users can still see some savings. For example, three smartphones with unlimited voice, texting and 6GB of data currently cost $200 per month on a Verizon Share Everything plan, while AT&T charges just a tad less at $195.

AT&T says the plan will be an option rather than a requirement for new customers and subscribers upgrading to a new phone. Verizon on the other hand is making them the only option for customers going forward, unless you stick with your existing plan and buy new phones at the unsubsidized pricing.