As has been said before, it is definitely a lot simpler to have a car in Los Angeles. Unfortunately, the public transportation system in LA is not the best, but many students have been able to use it very well and get around anywhere they need to. Cabs are options, but only when you can't get a ride from anyone else. Trains are great for a cheap and simple way to go to San Diego or Santa Barbara, too. For those who look hard enough, transportation to just about anywhere in LA is possible, although it might take a long time.
Those students that do not have a car should not worry, though, as there truly are many options available to get around. You should take the LA Metro buses as much as possible and get to know the system. While it can take a while to get around, those that know how to use the bus system in conjunction with the rail lines and other forms of transportation can often have an easier time getting around, especially when they don't have to find parking at a busy area. Most students that felt a car was essential had done very little on the bus, and many students that did have a car still used the bus quite often for trips into areas such as Chinatown, Pasadena, or Glendale. While the mass transit options and cab services are not as glamorous as certain other places in the world, Occidental students still certainly have many ways to get around if they are open to trying new things. Use the bus and rail lines when possible.