I'd doubt my sanity :) But if I was convinced I had something interesting, I'd send it to my friends before making it public. If I didn't have friends who were respected theorists, I'd post it to a cs-theory mailing list. Most importantly, I wouldn't title it "P != NP"; I'd rather say, "here's a line of thought that might have implications for P =? NP; please tell me where I'm going wrong."