[LeafStorm]

I don't think there's a concrete, universally accepted difference. Pretty much everyone has their own definition of "geek" and "nerd," and how much they overlap, and most of those definitions are mutually incompatible.

Also, http://xkcd.com/747/

[cyrus_]

People can have different, mutually incompatible definitions of the two, that's fine. All I'm saying is that very few people who have any opinion on the subject think the two refer to the same set of values and behaviors.