This article was amended on Thursday 16 July 2009. Moon-landing sceptics were referred to as "loonies", contrary to the Guardian style guide. This has been corrected.
This seems to be pushing politesse more than a bit too far. I mean 'sceptic' sounds nice and moderate and rational and sciencey: disbelieving things like the moon landings is, indeed, the pastime of people better described as loons.
Such distinctions, I think, should be maintained.