What are some alternatives?
When comparing Ajax Domain Finder and namegrep, you can also consider the following products
Machiname - Machiname is domain name search tool that lets you enter keywords and it will look up domains availability for every combination
Wordoid - Wordoid is a web application which helps to solve a common problem
DomainHole - DomainHole has the tools to allow you to find a great domain name.
Domainr - Domainr
BrandBucket - The original marketplace for business names and creative domain names.
Lean Domain Search - Find a Great Domain Name w/ twitter handle availability