Based on the work of some Israeli linguists, this algorithm looks at a chunk of text and guesses whether or not the author was male or female. In the original study it guessed correctly something like 90% of the time, though the web-based tool has a lower success rate.
A quick rundown of the blogs I tested:
Me - Consistently guessed male Adrienne - Mostly guessed female, one false male guess Budman - Consistently guessed female Sean - Mostly guessed male, one false female guess
I'm not sure what this proves, apart from the fact that Budman apparently has a very feminine writing style.