AT&T (T) announced last month that its new shared data plans would become available in late August, and now the carrier has set the launch date for its new “Mobile Share” plans: August 23rd. The new plans, which allow users and families to share buckets of data between multiple smartphones, tablets and notebook computers, start at $40 per month plus $45 per smartphone for 1GB of data. The plans top out at $200 plus $30 per smartphone for 20GB of data, and tablets and laptops can be added for $10 or $20 per device, respectively. Subscribers can add feature phones as well for $30 per device, and all plans include unlimited voice calling and text messaging.