I guess it depends on the word and if it is one that you never really see written down or not. I think if you look up the spelling of yacht you are cheating, but if you look up Tegucigalpa or something I would not really consider it cheating (though I am against it personally. Whether you see the correct spelling during or after the quiz, in both cases you can learn from it. And actually getting it wrong is a good reminder of how to spell it)
I guess looking up spelling of places and names feel less like cheating than looking up objects terms and verbs
"A typhoon differs from a cyclone or hurricane only on the basis of location. A hurricane is a storm that occurs in the Atlantic Ocean and northeastern Pacific Ocean, a typhoon occurs in the northwestern Pacific Ocean, and a tropical cyclone occurs in the south Pacific or Indian Ocean."