I recently conducted a study on this for my English class.
"Geek" is a person who bites the heads of chickens, but this definition no longer applies, as the word has been appropriated to people who tend to obsess over a single topic and know it inside out, are intelligent, have poor social skills, and usually means a computer person. This word, as far as I use it, has been approprated by Geeks in a similar manner to "Nigger" by African-Americans, or "Queer" by Homosexuals. If a non-geek is to use the word, it is an insult, but if a geek uses it, it is an observation or compliment.
Nerd originated from a Dr. Seuss book, and came into use to describe nerds in a similar way to geek. It is used to same way, although the differences between Nerd and Geek are often debated. I've heard everything from "Nerd is RPG's, Geek is computers", "A geek is a Nerd who transcends Nerddom, and actually has social skills" to "A Geek is Basically a Nerd, but not as good, they're not smart or haveNerd Talents"
Make up your own mind, but I'll be nothing but honoured if you call me either geek or nerd...as long as you are a geek or nerd yourself.
BTW, a Stormtrooper would murder an Orc. It has a gun, and it's a little known fact that Stormtroopers can shoot straight, they were just under orders not to in the movies. Darth Vader wanted to Dual Skywalker, so he made sure they gave him a challenge but let him live.