Question: I am working to integrate data from an external web service in the client side of my appliction. Someone asked me to test the condition when the service is unavailable or down. Anyone have any tips on how to block this site temporarily while we run the test to see how the service degrades?

For those curious we are testing against Virtual Earth, but Google Maps but this would apply to any equally complicated external service. 

any thoughts and suggestions are welcome

Answer: 
Create some Mock-Webservice class or interface (and [inject](http://martinfowler.com/articles/injection.html) [it](http://www.youtube.com/watch?v=hBVJbzAagfs)). In there, you could test the response of your system to webservice failures and also what happens, if a web-service request take longer than expected or actually time-out.

DeveloperWorks article on mock testing: <http://www.ibm.com/developerworks/library/j-mocktest.html>
How about blocking the domain name(s) in question by putting a nonsense entry into the `hosts` file?