What is tempuri.org?
namespaces, web-services
Solution
Webservices require unique namespaces so they don't confuse each others schemas and whatever with each other. A URL (domain, subdomain, subsubdomain, etc) is a clever identifier as it's "guaranteed" to be unique, and in most circumstances you've already got one.
Problem
Why does tempuri.org exist? Why does each XML Webservice require its own namespace, unique from any other on the web?