true, it wouldn't do a 100% job, but it would be another line of defense. the reason I was wondering about it was that the gp cited an example that was easy for humans to miss, but would be caught at once with a spell checker.

there are also statistical methods to detect words that are changed into other, valid words - check out the grammar checker in google docs for instance. again, not 100%, but every bit helps.

It would probably also throw out a lot of false positives which would take time to check. Especially in works of fiction, writers could take liberties with non-standard spelling.