I am blogging this because I am going to try and amend the wiki and I need a citation to do it. Shhh don't tell wiki. Or some wiki people will come around to my house and read clarrifying statements to me.
This is a run on from the recent Nerd Vs Geek debate, which is covered under the wiki for nerd. Anyway this is my theory.
A geek is someone who is articulately passionate about a particular subject but where that subject does not unduly lessen his chances of gettin' some sweeeeeet.
A nerd is one who cannot articulate their passion and the chosen subject is boring to most, and therefore does reduce their chances.
For example, a geek is an enthusiast whose passion for say computers does not neccessarially impinge on his ability to commence sexual relations with another person.
Where a nerd whose keen interest for calculus and inability to express that interest clearly does.
Sure some subjects will waver from geek to nerd in interest. For example in the early days before normal people used computers you were a nerd if you liked computers. Now, not so much. Ditto computer games. Nerd if you played Zork or Ultima III. Now not at all.
Basically if the chicks dig a subject as well then chances are you're not a nerd but a geek. But things like collecting train time tables will always be nerdy.