All the pure CSS methods I've seen have either produced not particularly attractive results or didn't work too well cross-browser. I'd create the whole text and shadow as a graphic and then use image replacement to insert it into your page.
Drop shadows created with CSS alone (just code without the aid of images) are not nearly as smooth as those created in say Photoshop - they may very well be someday fairly soon - that day has not yet come.
Using image replacement as Tyssen suggested, is the way to get consistent, predictable results across browser.
If not on text, you can easily use CSS to apply a drop shadow from a sliced image created in an image editor which will work cross browser and is not dependant on a proprietary browser filter/code snippet.