What comes first in my mind,whenever I am thinking about creating a shadow text,just go to photoshop and uses shadow property(inner shadow ,outer shadow) ,but css3 provides a just a single line of code.
To apply text shadow onto an element, add this CSS property in its style definition.

text-shadow: 3px 3px 4px #000;

The text-shadow property looks cool, but it is currently not supported by major browsers including Firefox 3.0, but will be supported in Firefox 3.1 beta. Browsers that support this CSS3 property are Safari 3+, Konquerer, Opera9.5+ and iCab.

For example,

This text will show a drop shadow in Safari, Opera or other supported browsers.

Here first two values are offset of shadow from original text corresponding to right and top offset respectively while third numeric value is the amount of blur radius that causes pixels of the shadow text to stretch by the specified amount.

Positive values for right and top offset will position your shadow to right and bottom while negative values will change it accordingly.

You can play with offset and blur values to create really nice looking text effects just with CSS. If you have been using this property for a while and created some really nice looking effects, let us know in comments below.

Why text-shadow is good?
The main goal of this property is to give designers and css coders a tool to make text effects, which could only be done before by rendering text as images with all the side effects. Text rendered as an image isn’t searchable and therefore very undelicious for search engines. Another side effect is the fact that images can be way more bigger as one small line of code in terms of file size. As you may know most css-files, which contain the whole layout of a website, are smaller than one image on most websites. So it’s really clever to use a css function instead of images for reducing unnecessary traffic.