An eggcorn is kind of like a malapropism and kind of not. A classic example is to replace the phrase "all intents and purposes" with "all intensive purposes". Most of us have probably laid our fair share of eggcorns without realizing it, but when you write it down it can’t be missed. Reading the comments on Skatje’s blog today I noted an interesting example:
I′d have to say that from reading your posts here, you′re pretty much the spit and image of Dad. #
Someone else later pointed out that it wasn’t actually an eggcorn, and lo, they were right; both "spitting image" and "spit and image" are valid, and although the former is now far more common, the latter actually predates it.
Then almost immediately I spotted another bona fide eggcorn in a comment on her father’s blog (where I spend far too much time) coincidentally appearing in a sentence that is in fact a response to the first example:
Moreover, the implication that all of PZ’s children being athiest means he has indoctrinated them is bold faced wrong. #
This is a perfect eggcorn (hope it’s not a typo), in that it sounds like the original bald-faced, carries much the same intended meaning, and as a bonus is quaintly relevant given the context in which it appears.