http://mr21.fr/jquery-selection/

DOC jquery-selection.js

// `yourElement` can be a NodeElement or a jQuery object as you want.
var selection = $.plugin_selection(yourElement)
	// `.applyThis` is useful if you want to specify the `this` for all your callbacks.
	// By default it's `window`.
	.applyThis(object)
	.onElementsAdded(function(jq_elems) {
	// This callback is called when some elements are selected.
	// Here, `jq_elems` is a jQuery object who contain the new elements selected.
	// This object doesn't contain only one element if the user use the shift key.
	// In this callback the `this` pointer is `window` by default
	// or it's the object you specify with `.applyThis`.
	})
	.onElementsRemoved(function(jq_elems) {
	// Same behaviour here.
	// If the user unselect all his items in the same time
	// `jq_elems` will be a jQuery list.
	});

// Here you have an access to the list of the elements actually selected.
// This array is automatically updated (it's not a copy).
var elSelected = selection.getArraySelection();

// By calling `lockCtrlKey` you lock the Ctrl key.
// The user can't unselect all the items by clicking around.
// There is also a `.unlockCtrlKey` method.
selection.lockCtrlKey();

// You can disable the shift key if you want.
// There is also a `.enableShiftKey` method.
selection.disableShiftKey();