What are some alternatives?
When comparing Ajax Domain Finder and Instant Domain Search, 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
Lean Domain Search - Find a Great Domain Name w/ twitter handle availability
DomainHole - DomainHole has the tools to allow you to find a great domain name.
NameBounce - NameBounce is an intelligent domain name and business name generator. Discover hundreds of new business name ideas with available domains, all for free!
namegrep - Domain name search with regular expressions and curated sets
Domainr - Domainr