CSS3 is exciting stuff. I really like the drop shadow feature because I was tired of always having to create new PNG files just to get the effect. Also, it's a pain trying to get the bottom lined up, and the right side of a div to all look right with the shadow. What a relief it is to let the browser figure it all out!
So, what are the tags?
Just like the CSS3 rotating text, each browser has its own tag. I haven't figured it out for Opera yet, but I'm sure that's ok. Very few people are using it anyways, right? So...here's the tags.
filter:progid:DXImageTransform.Microsoft.DropShadow(sProperties)
-webkit-box-shadow: 10px 10px 25px #ccc;
-moz-box-shadow: 10px 10px 25px #ccc;
The first one, the filter is for IE (details), the webkit tag is for Chrome and Safari (details), and the moz-box-shadow tag is for Firefox (details).
Properties
Webkit and Mozilla
The properties are pretty simple. They pretty much go as follows: