You don’t need javascript to do that. There are many different effects created with CSS shadow filters and things. Here are some sites for more help on this:
Mandarian Design and css experiments.
According to A List Apart you cannot do the dropshadow effect without extra divs, ergo I want a js that will automatically add the extra divs to the img tags.
According to the two sites I listed above, it’s done all the time and javascript is not needed to add DIVs to anything. I’ve done it plenty of times, using borders (silver or grey border on right and bottom), double layers of DIVS with background images using the z-index, using the various MSIE and other browser filters to create a shadow or drop shadow, and many other techniques and NEVER used javascript to create the shadow effect.
There are many ways of doing the same thing, I like keeping things simple.
The link in this thread will take you to a page where there are all the instructions, as well as links to some css, images and a modifed quicktags file that add the drop shadow divs.
http://wordpress.org/support/topic.php?id=30079#post-169994