The YahooGeoCode mashup service wraps with the http://developer.yahoo.com/maps/rest/V1/geocode.html Yahoo! Maps Web Services Geocoding API. It returns a specific latitude and longitude for a given address.
Running the client
Before using the geocode service, register for a Yahoo API Key and use it to provision the service (write-once only). For more information, go to http://developer.yahoo.com/wsregapp/index.php
For sample purposes (though it kind of defeats the exercise) you can use ours: rPJmz.HV34Hn654ySbBEOJf2i4nuae6LqGKX5EmrN30Q9aTeabb3vwThv2jRDN.rf3aAIw--