Seeing as my username is treehugginggeek
, I suppose that I should point out what I mean by "geek", as I know that many do not know the correct definition of the word.
A "geek" is a person with an intellectual interest in something outside of what the mainstream calls "normal". Geeks are more interested in whatever area of geekdom they have (computers, politics, art, etc) than conforming to the norm. Geeks rarely do more than the minimum in school, unless the subject pertains to their geekdom.
A "nerd" is a studious, school-obsessed person, who stereotypically would have the thick, black glasses and the pocket protectors (although no nerd I know wears such; my nerd friends tend to wear "unusual" things, whereas us geeks just wear plain, labelless clothes). Nerds, unlike geeks, do the maximum in school.
There is, of course, much overlap between the two labels, such as an interest in technology and/or speculative fiction. I've also seen "nerd" defined as a geek whose geekdom is schoolwork, with "geek" being defined as a category of nonconformists who focus on their areas of geekdom to the extent where they are oblivious to social norms. Both types may or may not be a "dork", who is a person who is utterly socially helpless.
Another way to illustrate the difference between the two words is that, arguably, the most famous self-proclaimed geek of modern history is Kurt Cobain, wheras Bill Gates would be, arguably, the most famous self-proclaimed nerd. Quite the difference between the two.
Here's another way to put it:http://www.catb.org/~esr/jargon/html/G/geek.html
As well as the Wikipedia definition: A person with a devotion to something in a way that places him or her outside the mainstream. This could be due to the intensity, depth, or subject of their interest. This definition is very broad, and allows for math geeks, band geeks, computer geeks, politics geeks, geography geeks, geeks of the natural sciences, music geeks, history geeks, Good Eats geeks (Briners), linguistics geeks, sports geeks, figure skating geeks, SCA geeks, gaming geeks, ham radio geeks, public transit geeks (metrophiles), anime and manga geeks (otaku), Stargate geeks (Stargate SG-1/Atlantis fans, Gaters), Buffy the Vampire Slayer and Angel geeks, Star Wars geeks, Star Trek geeks (Trekkie), Tolkien or fantasy geeks (Tolkienite), geeks of many colours, genders, and styles, and last but not least, Wikipedia geeks. Late 20th Century and early 21st century
Finally, as Phdcomics.com put it:
edit: backdated from July 5, 2005