Accounting for margin with position()

Accounting for margin with position()

This issue seems so perplexing to me that I feel I must be missing something obvious.

I want to get an element's "left" position within its offset parent with position().  But position() apparently returns the value of the outside of the element's margin.  For example:

  1. <div id="container">
  2.     <p id="par">This is a paragraph of text.</p>
  3. </div>
And the styles:

  1.     #container
  2.     {
  3.         background-color: #EEEEFF;
  4.         padding: 0;
  5.     }
  6.     #par
  7.     {
  8.         margin: 10px;
  9.         padding: 10px;
  10.         background-color: yellow;
  11.     }
The paragraph's own margin shoves it 10px to the left inside its container.  But $('#par).position().left is 0.

I really don't understand why I would ever want the value of the outside of an element's margin when trying to get its position.  That's beside the point, though.  What technique can I use to get an element's position where it actually starts, i.e., inside the margin?