Ars Technica has a good article on the recent re-implementation of the @font-face tag which is supported in Firefox 3.5 or Safari 4. Basically, it is allowing web designers to have a font used in a web page that is stored on the web server. For example, here I am using the font "Jellyka":

Don't forget to take a look at this page in IE. Quite different! Which is why it is still important to do a browser check.

Notice you can still highlight the text since it is not an image, just text with that font applied.

A good explanation on how to use the @font-face tag is here. Here is another good example of its usage and what it is about.