Internet Explorer 5.5? That was unexpected! :)<p>Documentation about drop shadows in IE 5.5: <a href="http://msdn.microsoft.com/en-us/library/ms532985(VS.85).aspx" rel="nofollow">http://msdn.microsoft.com/en-us/library/ms532985(VS.85).aspx</a>
Doesn't work with firefox 3.0 - seems like you'd be better using two elements, transparency, and z-index. This "old fashioned" way the shadow will work on all browsers it doesn't take much more code than his example.