Twitter Fast Follow supports tweets on the go

Twitter has launched a service which allows anyone to receive real-time tweets on their phones even if they are not signed up to the micro-blogging site.

Fast Follow lets people receive tweets by texting 'follow@username' to 40404 in the US. The service is not yet available in the UK, but Twitter said that it is "working with carriers to bring it to other countries".

Other features include the ability to set SMS alerts from a computer by clicking on the phone icon that appears on a tweeter's name or avatar. Twitter will then automatically send a text message every time that person tweets.

Alerts can be set quickly from a phone by sending 'on [username]' or 'off [username]' to the same number. People can also can sign up to Twitter by texting 'signup' or switch off the service by SMS.

Those who just want to dip in and out of Twitter will find the new function particularly handy, according to the company.

"We've always been big fans of trusty SMS. In fact, sending a text was originally the only way users could tweet. This is why tweets are 140 characters; they need to fit into a text message," Twitter said in a blog post.

"We value SMS because it's simple, instant and universal. Recently, we've added a few new features to make Twitter even more useful with SMS."

Twitter is also expected to release 'Twitter buttons', which will allow users to share articles on web sites and count how many times a URL has been shared, according to Mashable.

The button consists of a single line of code that can be added to any web site, and comes in three sizes with five settings for customisation.