On a related note, I have actually refused to tell some people my last name, because I know if they knew it they would find me on facebook and add me.
I know it would probably be easier to just delete my account or something, but that would require actually logging into facebook and messing with it. I'd rather just continue ignoring it.
Just use the privacy option to hide yourself from searches. Oh wait, I forgot, it's hideously bugged and doesn't always work.