Some research says that lurkers make up over 90% of online groups. I suspect that Less Wrong has an even higher percentage of lurkers than other online communities.
Please post a comment in this thread saying "Hi." You can say more if you want, but just posting "Hi" is good for a guaranteed free point of karma.
Also see the introduction thread.
From Newcomb's Problem and Regret of Rationality:
If it turns out that the techniques we advocate predictably lose, even though we thought they were reasonable, even though they came from our best mathematical investigation into what a rational agent should do, then we will conclude that those techniques are not actually rational, and we should figure out something else.