After years of messing with various solutions for the IE6 PNG transparency issue (if you don't know what that is, prepare to be bored out of your skull) which mostly involve a Javascript file that rewrites the page to take advantage of an IE-only CSS filter that renders the PNG images with correct backgrounds instead of a grey background. 

The trouble with most of those solutions is, when you apply them your links and input elements often go unclickable.  So you have to jump through yet more hoops for IE6 users, most of which require extra code and lots of headaches.  

I'm pleased to announce that today I stumbled on this astounding method of creating a PNG file that does away with all of the cross-browser issues of transparent PNG files: in modern browsers, the PNG transparency uses an alpha mask, so has the pretty anti-aliased edges and dropshadows that make you want to use PNG in the first place.  And in IE6, the PNG just treats all those semi-transparent pixels as transparent, so you get what you would have gotten using a GIF anyway.  I'll tell you how in a minute.