SO fiddle

Test Fiddle mainly for SO Questions

by Nick Craver

HTML

<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.4/themes/overcast/jquery-ui.css">
<textarea class="autoGrow" style="width:78%;height:75px;overflow:hidden" rows="6" cols ="80" id="input">Test Content
That
Needs
To
Be
    Expanded</textarea>

<textarea class="autoGrow" style="width:78%;height:75px;overflow:hidden" rows="6" cols ="80">Another
    Test Content
That
Needs
To
Be
Expanded</textarea>

JavaScript

jQuery.fn.resizeTextarea = function(min) {
  min = min || 75; 
  return this.bind("keyup change click focus", function() {
    var sh = this.scrollHeight;
    $(this).height(function(i, h) {
       return h <= sh && sh != 0 ? sh : min;
    });    
  }).trigger("keyup");
};

$(function() {
  $('.autoGrow').resizeTextarea();
});