Punctuation [ellipses and elides]:
The ellipse is possibly the single most overused punctuation mark by amateur (and many professional!) writers. The ellipse is represented by three periods (or "pips") in a row ("..."). It is NEVER less than three or more than three. It is ALWAYS three.
An ellipse is used to indicate an incomplete thought, and takes the place of a period. It should NEVER be used to represent a pause! If you wish to indicate a pause, a comma, semi-colon, or colon should be used instead. Generally, grammatically complete sentences should not end in an ellipse. Only sentence fragments (those sentences which do not possess a subject, verb, and object) should end in an ellipse.