Oprah Winfrey isn't Sen. Barack Obama's only secret to winning the Democratic presidential nomination. He has also jumped headfirst into the minority Internet networking world. It started when his team saw lots of traffic to the Obama site from Blackplanet.com, a social network of African-Americans with 16 million members. Kay Madati, the site's marketing boss, said Obama's folks reached out to him to create a profile page. It has worked big time, and Obama has since added profiles on sites targeting Hispanics, Christians, gays, and Asians. Obama's team says the social networking sites are a natural way to woo new voters. "Our approach to social networking outreach has also reflected our desire to make this campaign about not just one group of voters but millions who have not typically had a voice in the White House," says Obama spokeswoman Jen Psaki.