Smartwhois

SmartWhois is a useful network information utility that allows you to look up all the available information about an IP address, hostname or domain, including country, state or province, city, name of the network provider, administrator and technical support contact information. It helps you find answers to these important questions:

• Who is the owner of the domain?

• When was the domain registered and what is the owner's contact information?

• Who is the owner of the IP address block?

It is available from here.

A search for Microsoft.com returned a number of results including a number of subnets which when evaluated further gave a lot more contact information, obviously drilling down further would give you a lot more and all this information could be used later for a possible social engineering type attack if that was required for a particular Penetration Test.

This tool is unfortunately commercial and in my opinion the information gained can be obtained at no cost from other tools.  Still worth a few dollars if you want a nice GUI driven front-end and have a budget for a number of tools