Have we defined 'nerd' yet? My mind runs to the definition of a person who is socially inept yet academically apt. Nevertheless, within the realm of 'nerd', they range from arrogant to nice, funny to boring. Personally, I believe that when a person is humble and friendly, people are naturally drawn to them. Take my little brother for instance. He doesn't go out girl hunting, but the girls just come to him because he knows how to treat humans like people. He talks to them just like they are any other person. Plus, there is no ego to get past with him, so the conversation develops naturally and comfortably.
I think there is a misconception that hot girls know they are hot and use it to their advantage. Like Joca said, you just have to have the courage to get past that and talk to them. They're regular people with regular people needs; they're just a little easier on the eyes. I think the problem comes when guys treat hot girls like idols. That's where the fussy part begins.
Really, with girls (and just people and general), you have to be forward, the more forward the better. Of course, that doesn't mean blunt or tactless. You have to just completely throw yourself into the conversation and then let the talking continue without stopping to gawk at how great they look or always complimenting them. They aren't looking to see how great they look. To them, if this person wants to talk, then great, I'll talk too. If you sat on the bus beside a stranger and just started a conversation like you would with a close family member, they would respond and you would both have a really good time. You could start with "So, did you watch that Superman 5 movie? I heard it sucked. I prefer Christopher Reeve. He's a stud." Then you could just go with the flow. That's why RVers have such good relationships. You meet a stranger out in the RV park or at a gas station, you talk, and you have a great time with them.
Really, all great conversations are when you get past both of your masks. Why not start off on that note?
