jQuery Panels Plug-in
This plugin provides a simple and elegant abstraction level to your sliders / carousels / tabs / whatevernameyouwant. We simply call them panels. We observe that whatever their names are, those components have always the same logic: you can switch between their children. Maybe with a pagination, maybe with prev / next; sometimes with 3 items visible at once, sometimes only one. But the logic remains: you switch between panels.
So the plugin itself simply offers the API to deal with your panels, and is flexible and customizable throught its options. It does not do transitions by itself. You'll need to load a subengine that brings this behaviours. This is the killer-feature of this plugin: instead of loading a huge plugin with more options and capabilities, you only take the display engine(s) you need, and it's over.