Odf, my mother is German - immigrated to the US when she was 19 and she pronounces it "day-oh" or rather 'day-ah" - she seems to have troubles with the "o". I can see where people would think "Dai" should be pronounced "die" given the pronounciations of Tai Chi and Chai Tea but I pronounce it "day" and since it's my nickname/screen name, I can pronounce it however I want. ;-) But if someone accidentally ran into me at someplace and pronounced it "die-oh", I'd probably respond... after blinking in confusion a moment.

"Do not meddle in the affairs of cats, for they are subtle and will piss on your computer." -- Bruce Graham