What are some alternatives?
When comparing Short Domain Search and Instant Domain Search, you can also consider the following products
Agile Domain Search - Search great domain names for your website in seconds.
Lean Domain Search - Find a Great Domain Name w/ twitter handle availability
Undeveloped - Domains you never thought were available
namegrep - Domain name search with regular expressions and curated sets
Weird One Character Domain Superstore - Weird and available one character domain names
NameBounce - NameBounce is an intelligent domain name and business name generator. Discover hundreds of new business name ideas with available domains, all for free!