I had a thought last week. Say you wanted to build a simulated universe, and your simulation would contain intelligent beings. To conserve computational resources, you would want to avoid simulating aspects of the universe that are not observed by its inhabitants. It would be like a colossal view frustum culling process. For example, events that are very small or very far away from an observer might not need to be computed.
If our universe is a computer simulation, maybe that's why we see quantum mechanical effects. The detailed positions of individual particles remain in indeterminant states until they are observed, at which point their wave functions collapse (i.e. their states are computed in more detail).
Interestingly, this entire thought process assumes that the observer has a very important role in the simulation, as if the universe were designed for intelligent beings.