Twitter is the UK’s fastest growing website, breaking into the top 40 most visited sites in Britain for the first time.

The micro-blogging site has seen a huge rise in popularity in recent months, experiencing a 22-fold increase in traffic in the past year, according to Hitwise, the internet analysts. Twitter is now the 38th most visited site in the UK. At the same time last year it was 969th.

Robin Goad, Hitwise research director, said: “The noticeable thing about Twitter’s growth is that the vast majority of it has occurred during 2009. Media coverage of the site has escalated significantly this year and high-profile celebrity endorsements, by everyone from Stephen Fry to Ashton Kutcher, have come rolling in.”

Twitter’s profile continues to grow rapidly and it has been used as a key communications tool for Iranians protesting about the disputed presidential elections. Twitter provided the first witness reports of the Mumbai terrorist attacks and plane crashes in Denver earlier this year.

According to the new figures, Twitter has also become a key source of traffic to other websites. During May, links from Twitter accounted for 1 in every 350 visits to a website.

More than half of all links contained within Tweets directed users to sites such as social networks, blogs, news and entertainment sites. The figures also revealed that Twitter was the 27th most popular source of traffic to media and newspaper websites in the UK.

Other sites and services have benefitted from Twitter's seismic growth over the past few months. Twitpic, which allows people to share their photographs on Twitter, is now the third most visited online photo hosting website, behind Photobucket and Flickr.

Tweetdeck, a UK-based service that helps people to manage their Twitter account, released an iPhone application last week. It was downloaded about 100,000 times in the first 24 hours after it became available.