Most people use a specific username or alias across a lot of sites, as it is easier to remember and also, your friends could identify you easily in various sites with your username.
But it could be very frustrating, when you try to sign up on a new site only to find that your username is already taken. Checking for availability of your chosen username in several sites of interest could be a daunting task. Fortunately, there is an easier way.
Usernamecheck.com is a site, that you can use to check the username availability on multiple sites at once. You can type in your desired name Usernamecheck.com will scan over 60 social networks and services and tells you within seconds whether the username is available or taken. If it is available, it provides a link to the site, where you can sign up before someone else takes your name.