I also have never liked "pshaw!" as an exclamation. I've never heard it pronounced authoritatively - maybe because it doesn't recreate in writing anything that people actually say, even when sputtering. I get the "psh" part, but the "aw" ruins it for me. They should have stopped at the psh.

"I don't know which is worse: ignorance or apathy. And, frankly, I don't care." - Anonymous