How to know if user name still exist quickly

Maybe the site that I introduce to you sound like a little bit crazy, simple on layout usage, but function well. For example if we register in a site, such as to Blogger that registered pay a lot of time (it's so long for me), moreover it influenced by internet connection speed, that lately worse. Certainly we don't want spend our time useless. Beside that if we want to look for a username that still available or not in some of favorite website in the world, site that I reference for use and check, is the candidate of username that will we take still available or not. UserNameCheck, the name of site that I reference at this time it's very good and efficient for help us to look for is our username still availabble or concluded in some sites such us blogger, dailymotion, friendfeed, digg, corkd, brightkite, vimeom etsy, favtape, lastfm, flickr, Pandora, plurk, vox, wakoopa, rejaw, xbox live, xing, postreous, and many others that I can't spell it one by one. At this time there are 68 service that can perforate or collapse, but the collapse do not with hacking, but surely with their method, it can be with Ping or with API that available. User of username check is very easy, just entered the candidate of username that we want , and then push the "check" button, so the username will automatically checking one by one to service that available, then status that will give "available" by green font, but if username have take by the other user in service, then our status will be "taken" by red font. Username check use AJAX, so that our browser don't need refresh or change position to the other page that useless, so it can say very user friendly and efficient. So the conclusion, UserNameCheck very useful keeps the time and our energy only for some process that difficiult from website. just in few minutes, UserNameCheck help us without spend our time ono by one to pass the difficult sign up process.