Unless I'm missing something, the article can be summarized: "Guess the person's email address, check if the md5 hash of the address you guessed matches the Gravatar. If it matches you guessed correctly."

Nothing to see here. Move along...

In other news, all password hashes can eventually be cracked by brute force... Oh noes!

Apple's Airport Extreme supports IPv6 beautifully. :)

The double colon syntax for addresses with contiguous zeros makes this a lot simpler... ie) My home gateway is 2610:78:ad:1::1

Not too hard to memorize at all.