Select Element By CSS style (all with given style)

You can keep Mootools, or whatever you use... :)

function getStyle(el, prop) {
  var view = document.defaultView;
  if (view && view.getComputedStyle) {
    return view.getComputedStyle(el, null)[prop];
  }
  return el.currentStyle[prop];
}

​function getElementByStyle(style, value, tag)​ {
  var all = document.getElementsByTagName(tag || "*");
  var len = all.length;
  var result = [];
  for ( var i = 0; i < len; i++ ) {
    if ( getStyle(all[i], style) === value )
      result.push(all[i]);
  }
  return result;
}

In jQuery you could use

$('*').filter( function(){
  return ($(this).css('position') == 'absolute');
} );

[update]

Or even create a new selector.
got me interested and so here is one (its my 1st, so its not built for efficiency) to find elements by css property..

$.expr[':'].css = function(obj, index, meta, stack){
  var params = meta[3].split(',');

  return ($(obj).css(params[0]) == params[1]);
};

usage: $('optionalSelector:css(property,value)')
will return all elements (of optionalSelector) whose property = value

example: var visibleDivs = $('div:css(visibility,visible)');
will return all divs whose visibility is set to visible (works for the default visibility as well..)

For Mootools:

var styleEls = $$('*').filter(function(item) {
    return item.getStyle('position') == 'absolute';
});