Most developers usually takes advantage of Operation System Host File (commonly known as "hosts") to "trick" the S.O. and the browser to load websites and webservices from another server than the real production one.
It's a very easy approach to be able to use the production host name of your site or service while pointing your computer to another server (staging, Q&A, etc).
Some companies uses this strategy a lot, making a little dificult for developers to manage the huge amount of host names and IPs. In some cases developers needs to take care of thousands lines divided by several files. Everytime a server needs a different IP is a very boring job to update all these files.
With this problem in mind, we've created Change Hosts. A very easy to use tool that can make this job more efficient.Learn more about it here: http://www.coders.com.br/change-hosts
Great with DNS Flusher: https://addons.mozilla.org/en-US/firefox/addon/dns-flusher