Actress Jessica Biel and fashion designer Nicole Richie helped celebrate the wedding of their publicist pal Meredith O'Sullivan by jetting to Cabo San Lucas, Mexico over the weekend (01-02Sep12). Justin Timberlake's fiancee was snapped heading to a rehearsal dinner in a light blue dress at the Las Ventanas al Paraiso Resort on Friday night (31Aug12), while Richie was also said to be in town for the nuptials.