I must say that Hovind is a potentially a very necessary evil. If people like him didn't exist I'm not particulary sure how many scientists would take to explaining science to the general public. For one thing its very difficult to communicate effectively to the public and another it takes near infinite patience to do it well.
So in a way Hovind while propagating misinformation forces scientists to expend effort to in general educate the public. While this education does not get everyone at least a few people get it and then thats less ignorrant people left.
Unfortunatly the down side is that Hovinds stances since they do appeal on a popular level it makes it alot easier for him to generate public support for a potentially very wrong cause.
It would be nice if we had ethical and responsible public figures, it'd make life much nicer.