A trend I’ve observed in hour-long drama series lately is the desire to show, at the beginning of the episode, the most dramatic moment of that episode. Then, in brief bits, show the events leading up to that. Battlestar Galactica has used this in two mediocre episodes in a row now.
It’s a cheap, easy device to build tension but unlike, say, Lost’s flashbacks that reveal character and add layers of depth, these time shifts do nothing to increase our understanding of the situation or of the characters involved.
Time shifts can be used effectively. A great China Beach episode “Holly’s Choice” was told backwards, but did it to inventively reveal the small choices that led to a major decision. The movie Memento too was told backwards to great effect.
If you need to jump in time to increase tension and spark interest in the episode, my guess is that the story isn’t very strong.