I think it's only "tech" guys that really care for "100% standard compliance". My usual page consumers (= users) don't care if there's no alt-attribute for a "menu border picture element".
I usually just make sure that I don't see any obvious errors (all tags closed, all lower case, attributes in quotes, ...), but if it looks good on IE and FF, that's all I care for. I don't really care if I use a non-standard attribute in any HTML tag, so that the page doesn't validate against an DTD - as long as I get the visual results that I intended to get.
