I have heard this term thrown around so much that it's really lost all meaning.
Geek used to mean that you were smart, and knew way too much about things that the popular kids, when you went to high school, would have thought were stupid.
Not so much anymore, apparantly, as I just heard some guy refer to himself as a "sports geek." That would be awesome if maybe he was up on all the stats and played fantasy baseball or something, but no, he just plays a lot of sports and knows the rules for things like football, track, and baseball.
People who play a lot of sports are called "jocks." This term has not changed since I was in high school and doesn't seem to be going anywhere anytime soon. I know that jocks want to be considered cool in this day and age, but it doesn't mean they can just coin a label and BINGO you're inducted into this group. That would be like me walking around daily in a ball gown and tiara and calling myself aristocracy...fun to think about, but it doesn't change the reality. Maybe I'll just dye my hair blonde, put on long tons of makeup, watching American Idol, drive an SUV, act really shallow and then call myself a soccer mom, this is not fun to think about this idea makes my brain scream...and I think the sheer fact that I know who Isaac Asimov is, would exclude me from this group. (Perhaps I might be able to get away with this until I'd forget myself and utter the name Carl Sagan.)
'Geek' is a 'Nerd' with social skills, not just anyone who knows a lot about something. Geek has a special meaning and I wish to preserve that meaning. I know it's not a popular stance as geeks tend to be pretty accepting of people. I'm not really trying to be an elitist here...I can be friends with pretty much anyone, but I hate when people try to say that they are something they're not. Back in my day, they were called 'posers'.