There may be times when you need to know your external IP address. For some people this will be a fixed IP address whereas for most it will be allocated by the the Internet Service Provider (ISP) when you connect.
Your IP is:

What is an IP address? In simple terms, an IP address is much like your home address, telephone or credit card number, only itís used to identify your computer (or other network device). It works like a door to the world wide web, and without one your PC canít communicate with other devices or access the internet. Home users have the option of either a dynamic IP address, where new sets of numbers are assigned at regular intervals, or a static IP address, where your computer retains its one set address.