800,866,877 are the virtual PABX networks which provide toll free phone calls all over the world. This is a very effective method of saving money from phone calls. For many corporations, especially the business corporations, they need a toll free network for their phone calls. As a result, they use PABX for toll free system. In this system, there is a main line and the others are its sub-ordinate. You can call as frequent as you want but only the main line will be billed. That means you can be able to make a free call in that network. Many virtual, online sites and other authorities are now providing their services for 800 numbers. Another process that you can also use is the 800 Reverse Number Lookup. If you are looking for contact details of a business or a friend, but you cannot seem to find it in Google, try to use the 800 reverse number lookup. So if you want to make your lives easier, you can ask for further information from your 800 number providers. It can be said that 800 numbers are very useful for modern communication.