Jim Muth wrote a very good posting to the sci.skeptic newsgroup.
A former believer in UFO's, he details his disillusionment with the UFO field
after years of no sensible developments. The name of the article is
Confessions of a UFO Cynic.
Another sci.skeptic poster using the handle GuessWho wrote an excellent
comparison of Sky and Telescope vs. UFO magazine,
and had some interesting things to say on the relative merits of science
versus pseudoscience.