Web Inspector and Firefox Dollar Functions

Many of you probably didn't know this but WebKit-based like Safari and Chrome, in addition to Firefox, contain special dollar functions within the console object that allow you to grab elements within the current page.  While I've not determined the use of each method, a few of them are obvious:

// Dollar method
// Returns an element by ID
$ = function (id) {
	return document.getElementById.apply(document, arguments);
}

// Bling-Bling method
// Returns array of nodes found by QSA
$$ = function(selector) {
	return document.querySelectorAll.apply(document, arguments);
}

// Broke method
// returns the currently selected element within the console HTML pane
$0 = function toString() { [native code] }

The $1 - $4 methods are returning undefined, oddly enough.

It's not clear to me what the last few methods do.  Maybe they're placeholders for feature methods but they continue to be undefined for now.