Here's a list of sites / articles / hacks I once made, I hope you'll find something there:

The PNG problem in Windows Internet Explorer:
http://homepage.ntlworld.com/bobosola/pnghowto.htm

PNG Behavior:
http://webfx.eae.net/dhtml/pngbehavior/pngbehavior.html

TJK Design - PNG Overlay With No Extra Markup:
http://www.tjkdesign.com/articles/pn...tra_markup.asp

Improved PNG Behavior:
http://www.scss.com.au/family/andrew...n/pngbehavior/

Cross-Browser Variable Opacity with PNG: A Real Solution:
http://www.alistapart.com/articles/pngopacity/

IE PNG JavaScript Fix Tutorial:
http://www.designplanet.biz/tutorials-45.htm

MSDN AlphaImageLoader Filter:
http://msdn.microsoft.com/workshop/a...mageloader.asp

Cross-browser semi-transparent backgrounds:
http://www.daltonlp.com/daltonlp.cgi...=1&item_id=217

The Sad Story of PNG Gamma “Correction” (article):
http://hsivonen.iki.fi/png-gamma/

Ie's alpha transparency with AlphaImageLoader (test):
http://www.pmob.co.uk/temp/test-alphafilter.htm

IE7 PNG Transparency:
http://dean.edwards.name/IE7/