CSS Opacity and Transparency
Add this to the “How to make HTML behave more and more like Flash” pile.
Mandarin Design: CSS Opacity and Transparency
The article linked above has some great JavaScript- and non-JavaScript-based approaches to interactive opacity, and handles them cross-browser (well, on the PC, anyway).

September 8th, 2006 at 1:30 pm
http://msdn.microsoft.com/library/default.asp?url=/workshop/author/filter/reference/filters/alpha.asp
September 8th, 2006 at 1:34 pm
http://jszen.blogspot.com/2005/04/ie6-opacity-filter-caveat.html
September 8th, 2006 at 1:43 pm
http://jszen.blogspot.com/2005/04/ie-bold-text-opacity-problem.html