Wikipedia, "geek" is defined as:
A person who is fascinated, perhaps obsessively, by obscure or very specific areas of knowledge and imagination, usually electronic or virual in nature.But to step it up from Geek 1.0, according to Armano, "these aren't your parents' Geeks. These are the Geeks that invent the Facebook's Firefoxes and Flickr's of the world."
Bottom line: anyone with a passion about something specific, with a profound knowledge in that area - technology, literature, sports, music - is (or can be) a Geek. Hell, I'm a Marketing Geek!
Thanks to a number of well-placed and innovative Geeks, we now have the ability to share our geekiness through user-generated experiences, creating opportunities for others to share our knowledge and enjoy the thing each of us is passionate about.
The Geeks shall inherit the earth!