I've just written a jQuery plugin for this. It also uses the .data() method.

Registration:

I have wrapped / proxied the Backbone View setElement method to attach the required data to the view's $el property.

Registration is done behind the scenes like so:

$(myViewsEl).backboneView(myView);

Retrieval:

The plugin traverses up the DOM hierarchy (using .closest()) until it finds an element with the required data entry, i.e a DOM element with an associated view:

var nearestView = $(e.target).backboneView();

In addition, we can specify what type of Backbone View we wish to obtain, continuing up the hierarchy until we find an instance of matching type:

var nearestButtonView = $(e.target).backboneView(ButtonView);

JSFiddle Example:

Can be found here.

Notes:

I hope I am correct in thinking there are no memory leaks involved here; An 'unlink' is performed if setElement is called a second time round, and since removing a view's element calls .remove() by default, which destroys all data as well. Let me know if you think differently.

The plugin code:

(function($) {



    // Proxy the original Backbone.View setElement method:

    // See: http://backbonejs.org/#View-setElement



    var backboneSetElementOriginal = Backbone.View.prototype.setElement;



    Backbone.View.prototype.setElement = function(element) {

        if (this.el != element) {

            $(this.el).backboneView('unlink');                    

        }



        $(element).backboneView(this);    



        return backboneSetElementOriginal.apply(this, arguments);

    };



    // Create a custom selector to search for the presence of a 'backboneView' data entry:

    // This avoids a dependency on a data selector plugin...



    $.expr[':'].backboneView = function(element, intStackIndex, arrProperties, arrNodeStack) {

        return $(element).data('backboneView') !== undefined;        

    };



    // Plugin internal functions:



    var registerViewToElement = function($el, view) {

        $el.data('backboneView', view);

    };



    var getClosestViewFromElement = function($el, viewType) {

        var ret = null;



        viewType = viewType || Backbone.View;



        while ($el.length) {

            $el = $el.closest(':backboneView');

            ret = $el.length ? $el.data('backboneView') : null;



            if (ret instanceof viewType) {

                break;

            }

            else {

                $el = $el.parent();

            }           

        }



        return ret;                

    };



    // Extra methods:



    var methods = {



        unlink: function($el) {

            $el.removeData('backboneView');        

        }



    };



    // Plugin:



    $.fn.backboneView = function() {

        var ret = this;

        var args = Array.prototype.slice.call(arguments, 0);



        if ($.isFunction(methods[args[0]])) {

            methods[args[0]](this);                        

        }

        else if (args[0] && args[0] instanceof Backbone.View) {

            registerViewToElement(this.first(), args[0]);                

        }

        else {

            ret = getClosestViewFromElement(this.first(), args[0]);

        }



        return ret;        

    }        



})(jQuery);