Instant Domain Search

Instant Domain Search will search for the availability of a domain as you search. Its kinda of useful because it eliminates the need for pressing a button to see if a domain is available. The thing I tend to not trust with sites like this is they often setup domain tools to see which domains people have interest in. Once they find one they buy they domain and then sell it for a higher price. This is the reason that its said when you look for your domain be ready to buy because if you don't someone may and sell it for a higher price knowing someone wants it.

If you want a tool that is fast and records no information then check out Fast Whois Lookup.

Link:
http://instantdomainsearch.com/