Via The Inquisitr I came to Domize an ajax based search engine for domains.
“Domize is a secure, instant domain name search tool. As you type a domain name into the query box we immediately check its availability.”
It comes with an iPhone version and the live search is very fast. When you roll over a reserved domain you get a preview like in the screenshot below. Really good experience!
Here’s a list of some more services, including Dominize:
http://www.onlineobservations.net/do-you-like-to-collect-domains/