Getting The 'this' Scope Of The Caller

I'm trying to write an 'each' function for a JavaScript array that
behaves like Ruby's Array#each. (It doesn't matter if you know Ruby to
help with this question.)

My problem is the scope of 'this' inside the iterator callback. I would
like it to be the same as the object that called the each() on the
array. Right now I have to do that with a closure or an
explicitly-passed 'this' scope. For example:

function Person( inName, inCats ) {
this.name = inName;
this.cats = inCats;
}

// Using a closure
Person.prototype.showInfo = function( ) {
var me = this;
this.cats.each( function( catName ){
alert( me.name + " owns " + catName );
} );
}

Array.prototype.each = function( inCallback ){
for ( var i=0,len=this.length; i<len; ++i ){
inCallback( this[ i ], i );
}
}

phrogz = new Person( 'Gavin', [ 'Fuzzles', 'Kitty' ] );
phrogz.showInfo( );
--Gavin owns Fuzzles
--Gavin owns Kitty


// Using an explicit scope
Person.prototype.showInfo = function( ) {
this.cats.each( this, function( catName ){
alert( this.name + " owns " + catName );
} );
}

Array.prototype.each = function( inScope, inCallback ){
for ( var i=0,len=this.length; i<len; ++i ){
inCallback.call( inScope, this[ i ], i );
}
}


Inside the each() function, arguments.callee.caller would give me a
reference to the showInfo function object. What I am looking for is a
way to access the scope of the 'this' receiver within that particular
invocation of showInfo(), so that I can use it in place of inScope
without having to pass 'this' each call.