Calling any AT&T users from another AT&T mobile phone is always free regardless of when you do it. So, is AT&T to AT&T texting free? Unfortunately no, unless you opt for the $20 unlimited text messaging plan – that way not only texting to AT&T phones are free, any text to other mobile phones are free too, including pictures and video messaging.
Since texting between AT&T phones is not free, you need to take into consideration that any text you send or receive will count toward monthly limit. For beginners, the $5 plan with 200 texts is fine. But once your other friends start using text messages as a primary way of communication, you might want to upgrade to the unlimited plan to make all AT&T to AT&T Texting free (and other carriers too.)

December 30th, 2009
Tom
Posted in 
Correction Tom,
AT&T texting plans DO NOT include sending or receiving of pictures or videos. To do this you must have a Data plan as well as texting. If you do not have a Data Plan you will be charged $1 per megabyte of data in your text massages. This is applied to both sending and receiving texts. I just went over this with AT&T two days ago.