SAN FRANCISCO, US - BARACK Obama's stirring speech on racial division in the United States has become an online hit viewed nearly 2.5 million times on YouTube by Friday afternoon.

A video clip of Senator Obama's speech lasting 37 minutes and 39 seconds, an epic by Internet standards, has attracted the most viewers while video snippets of the presentation have been seen by tens of thousands of people.

'This speech made my eyes to water' one person wrote in an online discussion forum attached to the full-length Obama video. 'I almost started to cry.'

'Some folks placed the talk in a grand historic context. Many pundits praised it for its record-shattering honesty,' Molly McCall of Yahoo Buzz wrote in a posting detailing a surge in interest in Senator Obama's presentation.

'We can't tie them together for sure, but it's notable that queries for 'I have a dream speech' and 'Martin Luther King Free at Last speech' both spiked the day after Obama spoke.'

In his speech, the Democratic presidential contender described being the son of a white mother and a black father and then laid bare racial tensions in US culture that politicians usually avoid discussing.

The impetus for the speech was controversy over remarks made by Senator Obama's religious mentor and longtime pastor Reverend Jeremiah Wright.

'So Obama's got buzz,' Ms McCall wrote. 'Whether it hurts the candidate or not remains to be seen.'

Among popular speech-related videos on YouTube is a satire by comedian Jon Stewart on his politically oriented program The Daily Show.

In a video clip viewed more than 123,000 times by Friday night, Mr Stewart made sport of 'Obama talking to Americans about race as though they were adults.' 'This is a speech for intelligent Americans,' a person identified by the online name Quake132 wrote in a YouTube discussion forum.

'This is why I fear most Americans will not understand it.' -- AFP