Star Wars is at best "Science Fantasy". We could have a long, long, long discussion about all of the holes in it that would really be nothing more than a waste of server space. Basically it boils down to this: the SW milieu isn't based on any scientific principle, but rather Lucas' idea of how to make a space opera like the ones he enjoyed while growing up.
Science Fiction isn't just about space ships and laser/blaster pistols. Science Fiction is taking a scientific principle/theory/advance and speculating the impact on how humans would act in a situation like that.
Blade Runner is a much better example of Sci-Fi, since it's basically about the impact of genetic engineering on society. (Yes, there are some far-fetched things that will probably not be achieved for a long time if ever, such as memory implants.) SW and its ilk - e.g.
Battlestar Galactica - are space operas or Science Fantasy since they have little or no basis in science.
I don't know what it is, but some people actually seem to take offense - I'm not referring to anyone here specifically - at the notion that the SW movies are not Sci-Fi. I don't know why, since commenting on a misclassification doesn't seem to denigrate a film's entertainment value one iota.
Spazmo: How dare you forget to mention the Dean o' Science Fiction Himself?!
OTB