San Francisco  - Social networking site Twitter delayed planned maintenance to its system Tuesday in a move that it said was designed to minimize downtime for its users in Iran.

Twitter co-founder Brad Stone announced the move after the trendy social networking and micro-blogging site became a key conduit of information for Iranians protesting the contested election results.

The announcement wasn't just a publicity stunt from a site that was previously best known for updates from celebrities and the often irrelevant postings of hordes of fans.

In the days since the protests began, Iranians have turned by the thousands to Twitter as the government seeks to clamp down its control on other forms of communication. Reports from Iran, many of them on Twitter, say the government has shut down cell phone communications and is blocking land lines and text messaging.

Access to many websites also appears to be comprised, but networking sites like Twitter and Facebook remained accessible as users connected via proxy servers that hide their destination. It's not only Twitter that's helping the protestors. One group is even using Google Maps to show the location of rallies and where the government is placing tanks and snipers.

Making the impact even more profound was the fact that much of the mainstream western media failed to properly cover the start of the protests when they started on Saturday. CNN for example chose to air a repeat of the Larry King Show instead of covering the start of the crackdown.

By Monday Twitter was registering over 30 tweets a minute bearing the term "#iran election" - a tag that allows all postings on that subject to be easily found. It was easily the most popular subject on the site.

While talk of a "Twitter Revolution" in Iran may be exaggerated, even The New York Times agreed that the site was acting as a "virtual media office" for the supporters of opposition candidate Mir-Hossein Moussavi Hussein Moussavi, who use the site to coordinate protests and disseminate news.

Among the messages posted Tuesday on the site were "CONFIRMED!!! Army moving into Tehran against protesters!", "tehran is alive with sound of freedom" and "all cell networks down in Tehran."

One of the most prolific posters goes by the name Persiankiwi. "Attacked in streets by mob on motorbikes with batons - firing guns into air - street fires all over town - roads closed," wrote the anonymous contributor.

With information like that, even the US State Department asked Twitter to rearrange its maintenance downtime so that it would fall in the middle of the night in Iran.

Technology analysts were also impressed.

"I think this is Twitter's finest hour," said Ezra Gottheil, an analyst at Technology Business Research. "If anyone in Iran has access to the Web, they can tell their story. This has made our world smaller and more personal in a time of great chaos and when a government is trying to stop communication."

The rise of Twitter in Iran also reflects a fundamental shift in the nature of news, according to Caroline Dangson, an analyst with the technology research firm IDC.

"The situation in Iran is illustrating this phenomenon where government and media outlets are no longer the gatekeepers to news," she told ComputerWorld Magazine. "The man on the street is now the reporter in the field covering the situation in Iran thanks to the penetration of connected devices and availability of social messaging applications." (dpa)