HTML/CSS: How does Google create this drop shadow over their maps?

Question

Question: How does Google create the dropshadow next to the vertical scrollbar over the Google Map?

This is a screenshot depicting exactly what I\'m

Answer 1

It's actually a series of five razor-thin DIVs, each with decreasing opacity, stacked next to each other. You can see this for yourself by using Firebug and clicking on the shadow area.