SAN FRANCISCO -- San Diego-based agent Jordan Clarke got the call while on his way to show a property. It was a pair of clients, a couple who lived in Washington, D.C. They'd received a mobile notification from Redfin that a property matching their search criteria had just hit the market. Could he give it a look? Jordan Clarke with his iPhone 5s, iPad 3, Dell laptop and Powerbag, which has a built-in battery to charge his mobile devices on the go. Clarke checked the time. Judging he had enough before his appointment, he said he would. So begins Clarke's tale of a half day's work of digital wizardry that bagged his out-of-state clients an accepted offer on an unseen home in a matter of hours -- a tour de force of tech skill that the Redfin agent recounted during the Real E...