Steve Jobs followed a number of different diets, starting from his student days. It has even been suggested that his company was named Apple because of his passion for fruit. He did follow a fruitarian diet at times, at others following a 'raw food' diet that included carrots and other vegetables. However, before attempting anything like this you may want to check out what happened to Ashton Kutcher: He will play Jobs in a biopic, and attempted to follow his fruit only diet for a while. He ended up in hospital as a result with pancreatic problems.
There are people who eat about 75% fruit and they can manage to be healthy, though they may need supplements depending on what the rest of their diet consists of. Eating 100% fruit isn't recommended for long periods of time (Jobs didn't stay on it all his life either) and shouldn't be attempted until you have spoken to a doctor. You can get some ideas for fruit-only meals here.