Had the same problem, solved it in the following way:
entered class first and cheerfully said 'hello' whenever someone entered.
Consider this: nobody actually hates anybody else. To hate someone is to expend energies nobody wishes to do, especially not in school, and especially not among those your age (Yeah, i'm sorry if it seems patronizing, but I need to drive home the point) truly, it's not difficult to make friends. The point is that 'nerds' (aren't we all?) are usually having a smarter than normal approach on the matter, probably you don't know how to relate to the others, because where you speak of quad-cores and Ghz, they speak of soccer and football. Still, you can speak of homework! Or of the time, or of something else, like games.
The trick to making friends is either to go all-out or be smart about it. I can count people who I value as true friends on the tip of the hand, but peoples i am friendly with encompass the entirety of the city I live in. And i'm the most reclusive guy there is.
First off, start with your fellow on the side (in class, your desk is attached/near to that of another, right?) from there, move to his friends (If it's a girl, you have better luck trying with the guy in front, behind, or to the other side. Girls are both nicer, but also trickier, especially at the age.)
Key phylosophy is: don't be afraid to say hello, especially because nobody is going to gut you, maim you, kill you or outright yell at your face for it.
Once you start being the 'friendly' guy, everything's fine.
If not that you get the deal from the teachers that, just so casually, you have to placate bullies ire by sitting next to them (Ah the fond memories of brainwashing guys the double my height...)
>.>
Hope it helped.