It is visually customizable and exposes hooks for user-triggered events

FullCalendar is a jQuery plugin that provides a full-sized, drag & drop calendar

Watch Out AT&T: iPhone Sales Could Double By Dropping Exclusivity -

It seems to works even without installing the Firefox plugin. You can just drag and drop the button to your toolbar.

Source: Key Senate Democrat proposes dropping public option from heath-care reform

38 jquery-css выпадающих меню.