In the final weeks of the US presidential campaign, both candidates are using every tool in the box to help boost their support. And one of those tools can be a double-edged sword: robocalls.

It's the political equivalent of telemarketing. These automated phone calls are cheaper than TV ads and can reach thousands of targeted people in key states. But politicians also risk annoying potential voters, because few people enjoy unsollicited phone calls - especially around dinner time.

Here's one robocall, sent out recently on behalf of John McCain and posted by a user on YouTube who wants to end the practice:



McCain's use of robocalls has come under extra scrutiny, in large part because it was the same tactic that helped undo him in his 2000 primary battle with George W. Bush. He denounced the tactic earlier this year when it was used against him. And now, his own running mate is saying she's not a fan of the calls.

"If I called all the shots, and if I could wave a magic wand, I would be sitting at a kitchen table with more and more Americans, talking to them about our plan to get the economy back on track and winning the war and not having to rely on the old conventional ways of campaigning that includes those robocalls and includes spending so much money on the television ads that I think is kinda draining out there in terms of Americans' attention span, they get a bit irritated with just being inundated, and you're seeing a lot of that of course with the huge amounts of money that Barack Obama is able to spend on his ads and his robocalls also," Palin told reporters in Colorado Sunday night.

She also said that she would not ask her campaign to stop using robocalls.

Barack Obama has also used robocalls. With all the attention last week on "Joe the Plumber" from Ohio, his campaign went and found a different Joe the Plumber - from another swing state, Colorado.



The Huffington Post says Obama is now using this "other Joe the Plumber" in his robocalls. You can listen to audio from it here.

And some of the calls are just a little odd. Like this one made during the Democratic primaries, which features a recording of Stevie Wonder talking - and singing - about his support for Obama, which also found its way onto YouTube: