TMZ had caught her on tape breaking California law

SACRAMENTO, Calif. (AP) — California first lady Maria Shriver says she's sorry for breaking a state law that requires drivers to use hands-free devices while talking on cell phones.

The celebrity Web site TMZ.com posted two photographs and a video Tuesday showing Shriver holding a phone to her ear while she was behind the wheel. That prompted Gov. Arnold Schwarzenegger to write about it on Twitter, where he said "there's going to be swift action."

On Wednesday, Shriver said she will donate her favorite old cell phone to a program that helps domestic violence. She added: "That's my version of swift action with a higher purpose."

Schwarzenegger joked about the incident during a speech Wednesday at a technology conference in San Francisco, saying, "I'm in big trouble."

He said he couldn't believe his wife was caught on camera three times "holding that phone in her hand like in the Stone Age."

Shriver's statement did not say whether she would use a hands-free device in the future. Her office had no further comment.