[netnichols]

Funny, before I read the article I thought that "on accident" must be some British English bastardization since it sounds so weird to my American ears. But I was born in the late 70's and haven't lived in the US since 2000, so maybe that explains it.

[pc86]

I personally say "by accident" and was born in 86 (during the period the author says speakers are split) and "on accident" has always sounded odd to me, and almost wrong, although when I was in school I do recall people saying both with a pretty even split (as much as I can remember, anyway).

[klipt]

As a South African, the first time I saw "on accident" was from an American on IRC.

At the time I assumed he was just one of those uneducated redneck hillbillies I'd heard of who can't English proper. But it turns out that's just how young people speak these days.