Hi - my name is Dax and I am addicted to augmented reality!
In basic terms, augmented reality is the concept of replacing the visual reality with an alternative, or supplementing to it with additional information. To familiarize yourself check out this piece from 2008 with some examples of what could be done back then, and then take yourself over to ClickZ to read my latest "Will Augmented Reality Finally Get The Attention It Deserves".
It is Google that is grabbing headlines with it following their announcement of Project Glass - a pair of glasses that offer the wearer a heads up display of information that matters to them. There is a great piece on Search Engine Land by Danny Sullivan summarizing their announcement.
Enjoy! Be augmented.