Nerd – really really smart people, but usually lacking in the social skillz (unless pwning you in WoW / Calculus class counts as a social skill).

Geek – really really passionate about something (which becomes their geek domain). May or may not have the same high IQ as the nerd. Socially, they may vary from being the life of the party, to life of the D&D party.

Dork – people seen by other people as too ‘different’ — my psychoanalysis is that in reality, dorks remind people of part of themselves that they find too quirky or ugly, and that’s why they throw out this label with vicious prejudice. May or may not be inept in social skills, or other skills (i.e. they get labeled ‘dork’ in that area). Ranges from your typical geek/nerd, to the marching band player, to the guy with the stamp collection, to the guy who signs your checks.

Geek – I would attribute this more towards electronics, PCs. Most acceptable of the 3.

Dork – I would say more of inept towards common social practices like acting around women or in parties, etc..