Hi Mike, The Superfish plugin creates menus like this. It also has a few of important features that the Squirrelcart menu does not: - It degrades gracefully when JS is not available, in which case it falls back to a pure CSS dropdown menu ala suckerfish. This means search-engines can index the pages the menu links to, unlike with the Squirrelcart menu. - The ability to navigate the menu via the keyboard (Tab forwards, Shift Tab backwards) is retained for browsers that support it in the first place. - There is a timed delay on mouseout of the menu before the submenus collapse. This forgives mouse piloting errors and makes using the menu much easier. - Automatic usage of the hoverIntent plugin if it is present on the page makes the action of the submenus even more intelligent. This is not necessary, but is a nice option.
A big part of the reason that I created Superfish was because I saw so many dropdown menus that neglected these features and encouraged the view that dropdowns are bad for usability and accessibility. They still could be, but at least Superfish solves a few of the down-sides. Other jQuery options are jdMenu, which I hear good things about but I am quite unfamiliar with it and it's current state of maintenance. Also, I believe there are menu widgets under development for the UI library. Joel Birch.
