Reverse IP Address Lookup
An IP address is someone's virtual location. There is an IP address for every computer on the Internet and each one is made up of 4 bands of numbers in the format: 123.123.123.123.
IP addresses can also be in the format of URL's for websites. So "google.com" is an alias for an IP address and so on. To find out the IP address of a website, you just need to head to Whois.net - Find out who owns any web site and then type the web site address. It will reveal the IP for you. You can also use this IP / DNS information web site which allows you to see some more IP / DNS investigation tools.
Between those two resources, you can find out the information for any domain / web site. However, for email addresses such as joebloggs@hotmail.com, you will need to use a system such as the one provided by Gov-Records.com below: