Really really early teething

A friend (and regular commenter here) has a baby who is a week old. He is already cutting two teeth. When she mentioned this, I said, "Wow--my second was cutting teeth almost that early! It was awful!" and then we started talking a bit about it. At one point my friend said that she'd been frantically googling early teething and was getting scared because apparently sometimes early teething can be part of something else, so she was glad to hear that it had happened to my son, too.

So I thought I'd put my story and the basic facts of hers up here on the internet so anyone else googling frantically in the middle of the night newborn cutting teeth or newborn getting teeth or baby has teeth or newborn biting me or teeth?? or getting teeth at 6 days or OMG stop it with the teeth already can find a little signpost.

My second son's story: Nursed and slept like a champ from the get-go. Then at right around two weeks old he started drooling and being fussy and having drool stool and I saw two little teeth right there under the surface! Away went the sleep, and he was just generally peeved all the time, and the teeth were surging surging and there was a little sharp point on one of them, and then right before it broke through all the way, they sucked back into his gums! And then broke through for real at six months. But he had teething symptoms that whole time, from two weeks until they broke through at six months.

Flash forward: He's 5.5 years and has all of his teeth. They are small and have some spaces between them, but they bite just fine. Our dentist has said that that's normal, but that he also will probably never need braces because he has plenty of space between his teeth. Yay!

My friend (who might comment, but she has two older children and a newborn, so I don't think commenting will be her highest priority) says her son's teeth are poking through on the bottom, and have been since a few days after birth. He is biting her while he nurses (because he's so new to nursing) and doesn't really want to nurse because it hurts him. It's taking her whole bag of nursing tricks to help him eat. He's totally healthy, though--fat cheeks, responsive, and a sweet little dumpling. She brought up the possibility that these teeth coming through might not be his baby teeth but a third set, which I hadn't considered. But hey, any way you can shake down the Tooth Fairy...

Any other stories of aberrant teething--either relaly early or really late? The only late teething story I know is my friend's brother, who didn't cut a single tooth until he was 14 months old, but who is now happily married with a child and a post-graduate degree and a good job.