PNG Transparencies

I know PNG transparencies aren’t supported in IE6, and have found several resources that seem to half-fix the problem… I’m wondering if there is an easy plugin or a complicated fix that will do:

– HTML IMG tag PNG transparency fix
– External CSS File background-image transparency fix
– Above with overlayed URL linking support

It seems that many plugins are a mix and match of some but not all of those. A lot will handle CSS background tags if they are included in the HTML file but not if they are in an external .css file.