@GrahamLee - Dunno about that SSH callback product (sounds cool) but I like their opening line: "In an era of commodity exploit kits, drive-by malware, and crimeware-as-a-service, a second login factor isn’t excessive. It’s basic blocking & tackling to protect even user accounts (e.g. Google, Facebook, Paypal, World of Warcraft, etc.), much less administrative access."