I recently came across a high speed domain search called 10xwhois. This service shows the domain availability as soon as you type in the domain name. You can also save a list of favorite domain extensions and can also bookmark favorite domain searches.
10xwhois has support for keyboard shortcuts and you can also save your domain searches in a favorite list. This tool is a Java web application and is hosted on a dedicated server. It is designed to handle high volume requests and is probably the fastest domain search service on internet.
I am still working on a couple of enhancements such as domain suggest and 10xwhois widgets…
This tool also is a demonstration of the effectiveness of Ajax Web paradigm.