Alec Guinness was unable to attend the ceremony at which he was the eventual winner of the Best Actor award. This was due to him being in England for the filming of De la bouche du cheval (1958). Jean Simmons accepted the award on his behalf and it was presented to him at a dinner in London on 10th April 1958. Photographs of the event show Guinness holding his Oscar still in make-up and costume, having come straight from the film's set.
According to Lana Turner's daughter, this was the only Academy Award ceremony to be telecast without commercials. Source: book "Detour: A Hollywood Story" by Cheryl Crane.