Two quick ways to find out if a domain is available
Both services will check to see if a domain is taken as you type. At a first glance Ajax Windows would appear to have the edge. It has a prettier interface, and lets you search for 9 different domain types including .biz, info, us, ca, and uk.
But Ajax Windows is a bit on the slow side compared with Instant Domain Search, which, true to its name, shows results pretty much instantly. On the other hand, Instant Domain Search only checks for .com, ,net., and .org extensions. Of course, those are pretty much the biggies, right?
[via Killer Startups]