An app for the iPod Touch called Textfree assigns users a real phone number, and lets them send and receive texts for free. The trade-offs are minor. To text, they need to be connected to Wi-Fi and to deal with ads bannered across the bottom of the app. In the roughly two months since users of Pinger's Textfree app started getting assigned actual phone numbers, Pinger has handed out 1.6 million. That's as many wireless numbers as AT&T gave out to net new subscribers in April, May, and June. Pinger is now sending out about 630 million text messages per month; 70 percent of those are sent from iPod Touches, and 30 percent are sent from iPhones. The median age of the app's users is 18. See also Free Text Messaging Is Possible (New York Times) by David Pogue.