Spell checkers are good tools, but they aren't perfect -- as this poem demonstrates.
Every editor has had the experience of reading an article and knowing that the writer used spell-check, but didn't read it over on their own. The built-in spelling checker in a word processing program is a wonderful thing, but it's no substitute for close proofreading by a human being, as this poem demonstrates:
Eye halve a spelling chequer;
It came with my pea sea;
It plainly marques four my revue
Miss steaks eye kin know sea.
Eye strike a key and type a word
And weight four it two say
Weather eye am wrong oar write--
It shows me strait a weigh.
As soon as a mist ache is maid
It nose bee fore two long,
And eye can put the error rite
Its rare lea ever wrong.
Eye have run this poem threw it;
I am shore your pleased two no
Its letter perfect awl the weigh,
My chequer tolled me sew.