i think we're talking about honors courses, not latin honors.
graduate schools care most about what kind of research you've done as an undergraduate. if you've co-published a paper, then you've pretty much got a foot in the door.
ah. at my university we aren't allowed to take honors courses without being in the latin honors program, hence i've stopped differentiating between the two.
i didn't mean graduate schools in the PhD sense, only. i meant in the overall graduate/professional school (PhD, ScD, MD, JD, PharmD, DDS) senses. there, having graduated with latin honors would be a big advantage.