When Barack Obama announced his vice presidential pick last week to nearly 3 million cell phones, it was just another sign of how the presidential campaigns are taking advantage of new tools to get out the vote.

Thursday night in Denver, the Obama campaign began its push to November with 75,000 people and their cell phones.

The campaign urged supporters at Invesco Field to text message friends and sign them up as volunteers for Obama.

"The campaign is all about mixing the old with the new," says Josh Field, Seattle communications director with Obama for America.

When the Illinois senator announced plans to leak his vice presidential pick by text message, some 2.9 million people signed up. Because of that, the campaign has that many more people they can turn to to get out the vote.

"The bottom line is instead of stranger contacting you about Barack Obama, we want to give people the tools to go to their neighbors, go to people who know them and spread the message," says Field.

But the presidential campaigns are doing more than using text-messaging to reach potential voters.

From John McCain's Facebook page to personalized video clips, both candidates are using high-tech tools to a much greater extent than would have been possible even four years ago.

For the campaigns, it's all about making connections - and winning votes. And every one of those messages is strategically designed and timed.

University of Wasihngton professor Kiersten Foot has studied the Web's impact on politics in five elections, and she says online campaigning works.

"If you look at the data on how many people are voting and who's voting - even in the midterm elections in 2002-2006 - (you see) higher rates of voting than truly a decade ago," she says.

There's also a bigger community online. The number of bloggers at this democratic convention are four times the number in 2004, which explains why John McCain's got his Facebook page.

"I've always respected that about my dad," says the Republican candidate's daughter Meghan McCain as she posts video blogs on her web site, explaining to voters why her dad should be president.