AT&T mobile to mobile calling will be free to any mobile number starting Thursday, February 10th. What's the catch you may ask? You must have some type of unlimited messaging plan on your account. For individuals, the cost is $20 for unlimited messaging and for family plans, it's $30. You'll also need to be on a "qualifying" Nation or FamilyTalk plan.

Any of you plan on adding messaging just to get this feature? Or more importantly, is it swaying any potential Verizon switchers into staying with AT&T? I have a sneaky feeling this is the first of many deals both carriers will roll out to attract potential iPhone customers. Ah, gotta love competition!

[AT&T Press Release]