There is a big difference between Star Wars and Star Trek. Star Wars is more about entertainment; it's often funny and there are lots of cute characters. Don't get me wrong, there is still alot of 'serious' content and there are action sequences and alot of geeky details, but generally, Star Wars is more 'fun' - like ELT said, it's socially acceptable to be a Star Wars fan.
Alot of things are under the umbrella of 'Star Trek'. There was the old Star Trek show (think Spock). There was Star Trek: The Next Generation, Star Trek: Deep Space Nine (others, ELT?) There have also been many Star Trek movies. So the world of Star Trek is much, much more vast than the world of Star Wars. Star Trek is much less about entertainment value and more about geeky details and intelligent plots. Getting into Star Trek is like getting into Guided by Voices: it's like where do you start?, and you can never really know everything.
(Edited by jamiecarroll at 4:39 pm on April 11, 2002)
Relevant: Prince, PT Anderson, Punk, Post-Punk, Purple, Party of Five, Peter Swanson, Peter Gabriel-led Genesis, "Peter Panic", Paul's Boutique, Potential Energy, Every Features MB member but me.