There are just some words you can't teach people to spell. I've noticed a couple on NG that I see spelled incorrectly more often than not. Which words do you see misspelled far too often?
List:
Sequel - sequal, sequell, sekuel
Grammar - grammer
Retarded - retarted
Blammed - blamed
A Lot - alot, allot
Weird - wierd
Ridiculous - rediculous
Definite - defenite
Psycho - phsyco, physco
Hurt - hert
Some homophones excluded due to enormous number of possible mistakes.
Dekathos
retarded not retarted
Lambtaco
Yeah, but at least you can laugh imagining them pronouncing it that way.