It seems Facebook has u-turned on its strict decision to give users of the social networking site just one chance to choose their username - and then be stuck with it forever.

When Facebook announced the username scheme, which gave users the chance to nab a personalised URL, so, rather than the previous string of numbers, it warned users to "choose wisely" as once a name was picked, it was final.

When the username option launched, Facebook saw around 1 million users registering a name in the first hour while 3 million names were snapped up in the first 12 hours.

Although the company has made no official announcement, now in the username settings area is an account, it gives the option to change the username, with the new advice, "Choose your new username carefully. You can only change your username once".