"Extra's" host Mario Lopez admits he has texted on his cellphone while driving, but he's now helping Oprah Winfrey in a no texting-while-driving initiative.

Lopez makes an appearance on Oprah's show today to support the national "No Phone Zone Day." Oprah explains, "Texting or talking on your phone while you're driving is as dangerous as driving drunk!"

Mario adds, "This is an important initiative out here in L.A., where everyone practically lives in there car. They turn it into a mobile office."

The "Extra" host tells Oprah he proudly signed the pledge and got all the staff at "Extra" to sign as well. "No one is going to be texting and driving," Lopez announces.

"My biggest hope for the 'No Phone Zone' campaign is that it becomes mandatory," says Oprah. "That you can't have your phone in the car and use it while driving, just as seat belts are mandatory and drunk driving absolutely taboo. I'm hoping this not only becomes law but second nature for all of us. How many more have to die before we take a stand? Let their lives be our light."

Visit Oprah.com and take the pledge!