TV and the internet appear to be the formidable duo for being the principal sources of news and information among a growing number of American voters who will soon elect the next US president.

But radio remains a powerful medium for candidates.

The news website Politico said that Barack Obama has used radio to hammer rival John McCain with ads whose messages are far stronger than the Democrat’s more visible TV ads. Politico says Obama’s radio spots are proving to be effective.

According to the latest poll, Obama still leads McCain, 48-45, with the McCain saddled by George W. Bush who is credited for having the “the highest disapproval rates in history”.

For funny takes on US politics, the place to go is The Daily Show with Jon Stewart.

On Thursday night, millions of voters are expected to tune in to the debate between vice presidential candidates Joe Biden and Sarah Palin. A lot is at stake, says the Associated Press.

To prime people up, the New York Times came out with analyses on Biden and Palin that are good reads.

In Ohio, which may well decide the elections, voting has actually began. Same-day registration and voting is now underway until early next week.