Bloggers and web designers have been limited to a very small suite of fonts that they can be fairly sure are installed on almost all machines. A number of solutions have recently emerged to extend this range. Google offers a number of free fonts which your site or blog can reference. This allows your readers' browsers to automatically request the font from Google's server, and presto, you can use a non 'web-safe' typeface. The range currently available is limited, but hopefully as the popularity of this service increases, more will become available. Information on the blog plugin can be found here, and the official Google fonts blog is here.