http://www.dnsstuff.com/
If you put the website address in the last box on the left, you can get registration info about a website. If you have an IP address (that is a number) from an email use the bottom box in the middle.

http://headertool.apelord.com/
This utility will analyse a block of text (usually e-mail headers) and provide information about any IP addresses it may contain. The report identifies the probable country for each IP, and gives you easy access to an ARIN Whois record and any Google Groups hits for the IP.