Awesome, and I agree, super fast.
Could you put it up the very top of the side-bar? Would be a more convenient location to access it, imho.
Also, I'm sure some people might like to know if the search data is stored anywhere? 3rd party whois and availability checking services have been known in the past to poach domains (that they consider to be good) that people check for availability, and as such has made people more cautious about using such 3rd party services. Possible have a little "* No data is stored" or such note somewhere if that is the case.
Just playing devil's advocate mate, and not wanting to offend you. Think it is an awesome tool that I will surely use.