quickEach

gistfile1.js

// $.quickEach() replicates the functionality of $.each() but allows 'this'
// to be used as a jQuery object without the need to wrap it using '$(this)'.
// The performance boost comes from internally recycling a single jQuery
// object instead of wrapping each iteration in a brand new one.

// Development -----------------------------------
(function($)
{
	$.fn.quickEach = function(f)
	{
		var j = $([0]), i = -1, l = this.length, c;
		while(
			++i < l
			&& (c = j[0] = this[i])
			&& f.call(j, i, c) !== false
		);
		return this;
	};
})(jQuery);

// Minified --------------------------------------
(function($){$.fn.quickEach=function(f){var j=$([0]),i=-1,l=this.length,c;while(++i<l&&(c=j[0]=this[i])&&f.call(j,i,c)!==false);return this}})(jQuery);

// Usage -----------------------------------------
(function($)
{
	$('div').quickEach(function(i, el)
	{
		//'this' is a jQuery object
		//'i' is the index
		//'el' is the DOM element

		//Print the index of each element
		this.html('Index: '+i);
	});
})(jQuery);

You are correct. If you plan on referencing one of the objects again you will need to wrap it if you plan on using jQuery functions on it. In that scenario, you may be better off using standard $.each().
However, if you're storing a reference to the entire collection, then quickEach is still the better option. This is what you'd do:

var myCollection = $('div'); //You now have a variable referencing all of the divs

myCollection.quickEach(function(i, e)
{
    /* Do stuff */
});

//Later on, do stuff to the same collection
myCollection.quickEach(function(i, e)
{
    /* Do more stuff */
});

/* Do even more stuff */
myCollection.addClass('foo');