I don't know how Webster defines it but in my mind the geek loves Star Trek because of all the cool techi stuff and the nerd finds it interesting but can't get past the fact that the science is all carp. They both like complexity and both are interested in science but the for the geek cool matters more and the nerd cares more about concepts and what if possibilities. One of the biggest difference is that geeks don't really have social problems they just choose to relate to a none standard social group, geeks are very social within their clicks. Nerds are more likely to be loaners and really just want other people around so they can share their ideas with them.

Of course there is a lot of cross over between the two and some nerds are very geeky and some geeks are very nerdy but the opposite is true as well, I know some computer programming nerds who really have very little in common with the average geek. Nerds who are no better than the average schmuck with a PC because they really don't seem them as social tools and only care about the inforamtion they make available.

I know I consider myself a little of both but I lean much more toward the nerd than the geek.