A romcom that blokes can enjoy equally if not more than their partners, a deeply spiritual allegory that even agnostics can get a buzz out of. A great movie.
The genius of this story is the way it blends complex existential themes into thoroughly mainstream comedy (though Danny Rubin's original script started in the middle with a weatherman acting somewhat strangely...)
Phil Connors is a man who must experience the confines of infinite time in order to fully appreciate the freedoms of finite time. He learns along the way that days can be re-lived more easily than moments.
Slightly more cynically, you might also say that Phil surrenders his unique spiritual identity, albeit a jaded and egotistical one, in order to transform himself into the more featureless model of excellence he needs to become in order to win the prize of Rita's affection.
These are not parallel universes of the sort that we can experience indirectly through quantum interference phenomena, because from Phil's point of view they are stacked one on top of the other. It might be that he has mysteriously acquired the ability to subjectively explore each of his possible worlds one after the other, but there is a strong hint in the script that everyone else is in the warp with him, they just don't know it. (Rita's déjà vu episode.) If it wasn't that way, then we would have to assume that each of these todays is followed by tomorrows in which everyone else goes on to live the consequences that Phil has been so neatly dodging.
Anyway, parallel universes are identical at their points of connection, but those points are distinguished by distinct free choices. Each of Phil's Groundhog Days begins with him asleep, unable to be the agent of that choice.
Last week President Bush's State of the Union speech coincided with Groundhog Day.