Kara DioGuardi put her money where her American Idol judging mouth is on Lopez Tonight Monday.DioGuardi wasn't just a guest on Lopez's show -- she also performed. She and Jason Reeves sang Terrified, the song she wrote for former Idol runner-up Katharine McPhee. The performance was part of DioGuardi's Turner Broadcasting tour Monday night (April 19) -- she and her fellow Idol judges ...