I don't currently have a girlfriend, but in the past I have met them at school.
I feel there are two contributing factors to successfully getting a girlfriend.
One, is all about having confidence in yourself and I don't mean the "big and bad" type, I mean the I am very comfortable with who I am type. That other type won't really get you anywhere but failure. You may think its working at first, but in the grand scheme of things it not. Stay true to yourself.
Two, I hate to say it, but there are some really shallow girls out there (especially the younger ones). Alot of guys go well since I can't get a GF the problem must reside in me, which may be the case, but alot of the times its not. Guys hold girls above them sometimes, because lets face it, its easy for girls to get guys in this world, but they are STILL HUMAN. So what I'm trying to say is find a girl that not so shallow, which I understand they are few and far between. I feel alot of Aspie guys don't have girlfriends for this very reason.