//actionscript
[Bindable] var comboList:Array = new Array();
var myPicklistValues:ArrayCollection = new ArrayCollection();
apex.describeSObjects(["Task"],
	new AsyncResponder(function (result:Object):void
	{
		myPicklistValues = result[0].fields.Status.picklistValues;
		for (var p:int=0;p<myPicklistValues.length;p++)
		{
			if (myPicklistValues[p].active)
			{
				var foo:PickListEntry = myPicklistValues[p].label;
				comboList.push(foo);
			}
        }
	} 

}, genericFault));

//Flex code
<mx:ComboBox width="180" dataProvider="{comboList}" />