^ ^ IMO that's what validators are for. I have enough to do, I don't need the additional challenge of having a browser pick out every fallacy of my work - that's what competing developers and designers are for, and they do quite well. :-)
Also IMO, I'm ill of all this browser war stuff. What's wrong with being completely indifferent to what browser is being used? Obviously some browsers make your job more difficult than others, but the bottom line is the "average user" doesn't care, they just want to find their widgets and thing-a-ma-bobs.