A good article on typography and the web, from Slate magazine (of all places): Down With Verdana! Typography on the Web is basic and dull. A startup called Typekit will fix it.
Latest versions of most browsers no recognize the CSS rule @font-face that allows for the embedding of fonts in web pages. This page (screenshot shown below) demonstrates what can be done with @font-face (displayed in Firefox 3.5)
The company Typekit offers subscription based service for the licensing and use of fonts online.