I saw this coming, an iPhone-enabled credit card payment system. Square is actually a brainchild of Jack Dorsey, co-founder of Twitter. This isn’t for full-fledged mobile sites but for individuals/small business who want to make accepting credit cards easier for iPhone users.
Square is an iPhone credit card payment system from Twitter’s Jack Dorsey, and it has just entered public beta. Square lets anyone with an iPhone accept payments from a credit card using an iPhone app and a small card-reader dongle which plugs into the iPhone’s headphone jack. Square is different from other solutions because it is designed for individuals, not big-business. All you need to start is the widget and an account at Square.
See video of the Square Demo: