A white plastic "cube"* that is slightly bigger than a thumb tip protrudes from the top of an Android phone. A thin slit runs through it; peek inside and you can make out the interior metal nub capable of reading any credit card that swoops through it.
This is Square, an accessory to the recently released Android version of an iPhone app (hands-on) that's aiming to revolutionize personal mobile payments the way that PayPal first simplified payments online. We demoed the Android version of Square at the Google I/O developer conference on Wednesday in San Francisco. … Read more