For a long time web designers had to battle limited choice with typography and font usage for their creations. In order to make an accessible website, a designer was forced to limit their choice to a handfull of fonts--the other option was to make a lower utility site using images for text--not a favorite for designers that also love data and content.
HTML5 and other recent innovations in web design are beginning to open up the possibilities for design and aesthetics that were once once possible with print. Now, it is possible to add embeddable fonts to a webpage using CSS @font-face declarations and woff file types which allow web distribution and a true range of typographic choice for web design.
One great resource to help designers is the Google Font Directory, which allows users to browse a listing of all fonts that are available through the Google Font API. Fonts within this directory are managed under an open source license and are served by Google servers, which will certainly make them very appealing for graphic artists and remove the licensing barriers which make @font-face tasks challenging.
As the SAS model gains strength as a revenue model for web-based businesses, we are seeing a new market arise for typographic design for the website--websites that use a subscription model for hosting font collections for use in web design. Si
tes like fontdeck.com and typekit.com offer a slew of options that were previous not possible for designers. Essentially these websites rent the use of these fonts, which have restrictions for web distribution--unlike Google which offers fonts in it's directory at no charge using an open source license.