Am I strange if I am not on Facebook?

[Sine kwa non]

If you wish to pursue a career in sales and marketing it is indispensible. You don't have to chat if you don't want to.

[rizley]

definitely not. i'm 17 and i don't have one.

[Tye]

I find that people who are a lot older than you are using Facebook for their job search, to keep up with old classmates and colleagues. It was really aimed at the older generation anyway as a way to compete with MySpace. And no, you're not strange for not engaging.
Have you thought about using it just for the job search. It can never hurt.

[abraxas]

You could very well hurt your job chances by GETTING a Facebook.

Private Facebook conversations, posts, and comments are not always so private.

You're thirty years old: Just join LinkedIn. It's Facebook for grownups.

[aero]

Facebook won't hinder you in the job market.
As some answerers have noted, wall posts or photos that frame you in a less-than-good light will only work against you. (though you can close off the wall function and control the photos posted)

What only matters is showing the prospective employers that you can demonstrate communication, team work and good social skills, and build social/business networks (assuming the job requires this kind of thing). .