Some nice venn diagram about what makes a geek, nerd or dork:
http://www.buzzfeed.com/scott/nerd-venn-diagram
Recently a more scientifically approach was taken in a research about the difference between a nerd and a geek.. here are the results:
http://www.makeuseof.com/tag/are-you-a-geek-or-a-nerd-find-out-for-sure/