WASHINGTON - THE campaign of Democratic presidential candidate Barack Obama, in its latest bid to use Internet Age technology to trounce Republican rival John McCain and connect with supporters, has released free software that turns Apple iPhones into political rallying tools.

'Obama '08: The Official iPhone Application', available at Apple's online App Store on Friday, gives users 'the tools you need to make an impact and stay in the know', according to the campaign.

The application, which also works on iPod Touch devices that are essentially iPhones without mobile telephone capabilities, contains information on Mr Obama's positions on the issues, photos and videos from the campaign trail and news on the race.

The software enables Obama supporters to automatically scan their digital phone books for friends in states where their preferred candidate needs more support and uses GPS features in iPhones to find nearby Obama campaign offices or rallies.

'Making a difference takes only moments using the Call a Friend feature. Your contacts are prioritised by key battleground states, and you can make calls and organise results all in one place,' the campaign said.

It also features a green button marked 'Donate' for campaign contributions.

The Obama campaign has generally been more aggressive than that of Mr McCain in using the latest technology and the power of the Internet to raise funds and register voters for the November 4 presidential election.