My current employer (Giva, Inc) has released another jQuery plug-in today called the Linkselect jQuery Plug-in. This plug-in converts a normal <select /> element into a component that can be highly stylized via CSS. While there are a number of similar plug-ins already, there are a several of key differences which we think make this unique:
Drop down menus are intelligently positioned to stay in the viewport
Specifically designed to work in a limited amount of real estate
Specifically designed to work well with elements aligned on the right edge of the viewport
Full keyboard support (emulates IE6's <select /> element)