I was reading JohnCow (yes, the cow) and noticed a feature on his sidebar that I would like to implement, but I just can't figure out how to do it. On his sidebar, you'll see a narrow content bar, and then when you scroll down a tiny bit, a larger bar for ads is placed on top of it, complete with a nice dropshadow effect. Is this done with graphics drawn out on the top and bottom of the ad section?
Not sure what is confusing you on this site? The shadow effect is simply this image file http://www.johncow.com/wp-content/themes/johncow/images/adboxestop.gif and all the rest is simply handled by Divs