With 65% of U.S. mobile handset buyers going to carrier outlets and counters to buy all those handsets, that leaves the other 35% of US wireless customers looking at other sources for all those cellphones by our math; physical and online retailers pick up that slack. Which, exactly? Wireless Week reports that powerhouse retailers like Best Buy, Radio Shack, Target and Wal-Mart are (unsurprisingly) doing their part. Hey, are those calling plan commission bells we hear? Anyway, Wal-Mart has gained ground from the days of selling low-end phones and plans, offering a decent assortment from more than a few carriers these days; Best Buy is doing well also, while Radio Shack -- once chummy with several carriers -- is apparently being beaten badly by the bigger consumer electronics and discount chains, and the news that its outlets won't be getting the iPhone in store can't be easing the heartburn. Of course, we figure this kind of fierce competition can only be good news for consumers, so bring it on; if the big boxes want to beat carriers' corporate stores dollar-for-dollar on handsets, you're not going to hear a peep of complaint out of us.