AT&T Says Half a Million iPads Use its Network

"About a half a million iPad owners use AT&T's network to connect the Apple tablet computer to the Internet, according to the telephone company's top executive Randall Stephenson. AT&T, the No. 2 U.S. mobile service, is the only U.S. operator providing cellular connectivity for iPad, of which Apple said it sold 3.27 million units in the second quarter alone."