Your palmistry post is ancient, so I figured on replying to this one instead. I took a month-long palmistry class (free, taught by someone who did not claim to be a psychic of any sort) in 1999. And we dispensed with in the first 10 minutes of the first class, how to be a bad but successful palm-reader (or clairvoyant or tarot-reader or tea-leaf reader or astrologer or graphologist or numerologist or...). The next 4 weeks we concentrated on mounts and dermaglyphics and lines and phalange lengths, so I'm inclined to think, while charlatanism is rampant, there are real approaches to palm-reading (and likely those other disciplines as well) which are, if not actually revelatory, at least not intentionally horseshit.

And I'm willing to believe it can be revelatory too. A good deal of what we saw turned out to be basically amateur medical diagnosis (coloration, moisture, puffiness, nail spotting, etc., all of which are established as indicators of health). If one's health is imprinted on the hands, the imprinting of the personality doesn't seem that far-fetched.

This handwriting thing, though, yeah, is probably at least mostly crap.