so i did i wanted to share what i think is the best computer air intake filter keeps dust almost completley out of the case if you let it collect over few months or during dusty month it will find its way in threw in filtered cracks and just get pulled in enough to collect on the inside but not much will make it in even if you do it every 6 months at first i was having issues finding stuff like this but ive found the stuff that i got with a case in 2005 and now im finding it pretty easy you can buy a roll from amazaon here
also they have a web site here
the second link has snap on rings that you can put on the fans this filter is far easier then pantyhose and probably filters better too with out cleaning it as often.
actually i've thought of some ideas that makes pantyhose easier just put it over the outside of the inlet and secure it with a rubber band or big hair tie and cut off the excese in a way that you can reuse it some reason didnt think about that till now.