Does there already exist a widget which would allow the user to pick his/her choice from one of Google Webfonts fonts and you could embed this widget to your own web application?
http://www.google.com/webfonts
Some kind of advanced Font picker dialog with robust search and preview functionality, allowing dynamically to load Google Webfonts.
Does Google Webfonts expose the necessary listing and metadata to build such widget if one doesn't exist yet?