You can create beautiful drop shadows in CSS without the need for images (you know, like back in the olden days). With just a little CSS, you can create a few different drop shadow effects, like lifted paper drop shadows, perspective drop shadows, horizontal curved drop shadows, and vertical curved drop shadows. The example code is taken from a drop shadow demo page from a few years ago.
I remember the old days before CSS was widely used. They were dark days, indeed. When you wanted to place a drop shadow behind a photo on your website, you didn’t have a lot of choices except to place the drop shadow on the photo in Photoshop, and hope that the background matched. We’ve come a long way since then.