DAYTON, Ohio (AP) - John McCain has introduced Alaska Gov. Sarah Palin, a conservative who shares his maverick streak, as his vice presidential running mate in a startling selection on the eve of the Republican National Convention.

At a raucous rally Friday in the swing state of Ohio, McCain said he made his pick after looking for a political partner "who can best help me shake up Washington and make it start working again for the people who are counting on us."

McCain said that Palin was "Exactly who I need. She's exactly who this country needs to help us fight the same old Washington politics of me first and country second."

The 44-year-old Palin, a mother of five, is a self-styled hockey mom and political reformer who has been governor of her state less than two years.

Palin's selection is a surprise, as McCain passed over many other better-known prospects, some of whom had been the subject of intense speculation for weeks or months.

At 44, Palin is a generation younger that Joe Biden, who is Barack Obama's running mate.

She is three years Obama's junior, as well. McCain has made much in recent weeks of Obama's relative lack of experience in foreign policy and defense matters.