I'm a shy introvert, but I see this fellow's problem a mile away: he needs to get better at saying no to people. Sure it's important to be present for social functions, and there's an art to "making an appearance" that is just part of playing the game. But if you're consciously aware that you should be somewhere else... GO.
A room full of tech geeks will get this. Actually, they most likely won't notice that you're leaving. That particular neurosis is rooted in ego: part of you wants someone to notice that you're missing, so that you can be not just doing something important but be a hero about it.
Deep down, we're all frequently irrational in similar ways.
"I don't want to be alone, but I want to be left alone." - Stephen Fry