EN
We address the following question: How different can closed, oriented 3-manifolds be if they become homeomorphic after taking a product with a sphere?
For geometric 3-manifolds this paper provides a complete answer to this question. For possibly non-geometric 3-manifolds, we establish results which concern 3-manifolds with finite fundamental group (i.e., 3-dimensional fake spherical space forms) and compare these results with results involving fake spherical space forms of higher dimensions.