I hope this Square thing catches on, especially if it can help make every big retailer's checkout experience more like the Apple Store's. That is to say, turn every in-store salesperson into a roving register to speed things up. The startup, whose small attachment turns a smartphone into a credit card reader, got a further boost this week with payment giant Visa making a strategic investment in the company.

"America's Most Reliable Wireless Network" has been anything but in the last couple of days when it comes to 4G service. Verizon Wireless said today its high-speed 4G LTE network, which covers 45 U.S. cities, was restored this morning after suffering an outage that began late Tuesday. The shutdown has been especially embarrassing for a carrier that's long made reliability a central part of its marketing and corporate identity.

A new study from Retrevo today found nearly two-thirds (62%) of mobile customers feel stuck with outdated smartphones because their two-year contracts won't allow them to buy new handsets more frequently. At the same time, manufacturers are pumping out new models faster than ever. More than 120 smartphones were released from major vendors over the course of about a year, according to Retrevo.

Google released a batch of smartphone usage data today based on a new study it commissioned from market research firm Ipsos OTX, based on a survey of more than 5,000 U.S. smartphone users at the end of 2010. The upshot of the findings: people are using smartphones a lot for searching and shopping businesses, and advertisers should have a strong mobile presence and use the medium for marketing.

With the launch of its upgraded Nook Color e-reader today, Barnes & Noble has added more pressure on Amazon to introduce its own tablet -- in color.

Sprint Nextel has been one of the earliest and most outspoken critics of AT&T's proposed acquisition of T-Mobile USA. Sprint CEO Dan Hesse earlier this month said the mega-deal poses a "serious threat" to the industry and would eliminate competition from the wireless market by effectively turning it into a duopoly dominated by AT&T and Verizon Wireless. But in merger documents AT&T filed with the Federal Communications Commission yesterday, the nation's No. 2 carrier had only complimentary things to say about Sprint as a competitor.

So after Round 1 of AT&T and Verizon Wireless going head-to-head with the iPhone, the contest could be called a split decision, or in corporate parlance, "a win/win." AT&T survived the incursion of an iPhone-equipped Verizon, activating 3.6 million of the Apple smartphones in the first quarter, up 1 million from a year earlier.

A new comScore report today about credit card use shows people are increasingly turning to their mobile devices to access accounts and complete transactions. One in five cardholders who also own a mobile phone said they've used their device to manage their accounts over the past 12 months. Specifically, 16% accessed their issuer's site via a mobile browser, 13% through an app, and 13% through mobile text alerts.

Because of its vast population and surging economic growth, China has long been eyed by mobile companies and marketers as a fertile ground for expansion. The same essentially goes for the other so-called BRIC nations: Brazil, India and Russia. A new eMarketer forecast of mobile advertising in those countries probably won't do much to change that outlook.

Cable operators and networks have been wrangling lately over rights for the streaming of live TV over iPad apps. Both Time Warner Cable and Cablevision have riled cable TV channels with new apps that their respective customers can use to watch a range of programming on the Apple tablet from anywhere in their homes. Time Warner has gone to court seeking a declaratory judgment of its rights to stream network content through its TWCableTV app.