Checkdomain.com

Checkdomain.com is the place to go on the Internet to check to see if a domain name is available for almost every country in the world.

DomainSurfer.com

DomainSurfer is a great resource when searching for domain names. Its ability to perform partial domain name searches make it a useful brainstorming tool.

Netcraft

This tool allows you to search domains and sub-domains using a partial name.  You can search for names which begin with, contain or end with user specified word strings.  

NameDroppers.com

Namedroppers.com provides a domain name search engine that allows you to search for domain names using multiple keywords.

Nameboy

This tool is an intelligent domain name search tool. It suggests relevant and available domain names based on key words that you provide.