There are rice cookers you can purchase which will finish the rice according to a schedule. They're more expensive than the the average, but if you're going to use it frequently and you want rice ready when you get home, it's top notch.

Essentially, you measure you rice, clean it (as always) then add the water, leave it in the cooker, the the timer you want it to finished, and the cooker does the rest.

Edit: A thought on top of this: Sushi is often a mix of rice, vinegar, salt and sugar, then seaweed and a meat. If you have the rice cooker, most of the time for prep is taken out.