Fat Free CSS Drop Shadows
Most of the current publicized methods for implementing drop shadows in web design are far too excessive, some require wrapping the images in three extra divs, most rely on sliced images or sluggish javascript, but there’s a really simple method to add shadows to any block-level element without the need for any of this other faff, just pure, logical CSS.
As you’ll see in the examples, one can generate shadows of any width, in any colour and on any background. This technique is also rendered exactly the same in all browsers because, well, it’s just so simple (and simple solutions make me tingle).
Example: 2px Subtle Shadow
img.shadow {
background: #afafaf;
padding: 1px;
border: 1px solid #d6d6d6;
}
Note that the above code is suited for this site’s background colour, I figuring out what colours to use before simply copying and pasting the code.
The logic behind this is quite simple, pad the element with 1 pixel of spacing to reveal its background colour (which is set to an appropriate shade of grey), then set the element’s border to a 1 pixel solid, lighter shade of grey. This gives a subtle (and in my opinion, good-looking) shadow effect, and won’t give you any headaches in the long run. I recommend using Photoshop to create a 3 pixel drop shadow on a layer (using your site’s background colour as the document background) and use this to reference your shadow colours.
If you’d like to see some more examples and take a look at the code, I’ve set up an Example Page. Using the methods documented there you can generate shadows of any size, even though I do believe the more subtle look is much nicer.
I’ve used this technique on a handful of client’s sites, even on dark backgrounds and it always works wonderfully, and since there’s no extra images, tricky javascript etc, you feel a lot cleaner when using this 
