What's the best way to add a shadow effect to sides of page as seen right here?

[RedHotChili]

I read this post and was wondering if this is the best way to achieve this:

Originally Posted by LEAD_WEIGHT

This is the basic way of getting to what you want.

Try going by 770pixel width and add image to StyleVars => Page Background => Standard CSS Attributes => Background

#000 url(images/misc/pagebg.gif) repeat-y top left

|<---pagebg.gif---><------Fourm Content------><---pagebg.gif--->|
|<---overhang image---><------770px------><---overhang image--->|
|<-------------------Approx. 830px pagebg.gif---------------------->|

pagebg.gif are usally ???px width by 1px thick[height]

You can use CSS to get better results.

He mentions using CSS to get better results. Is this true? If so, does anyone know how this would be done? Is this how it was done here?

TIA