Jeditables is an inline/in place editing plugin for jQuery, which offers a variety of options and styles for editing content.
This plugin uses XHR for uploading multiple files with progress-bar in FF3.6+, Safari4+, Chrome and falls back to hidden iframe based upload in other browsers, providing good user experience everywhere.
Simple Star Rating System is a jquery plugin for star rating systems.
A jQuery plugin for searching the DOM. It lets you search within an element (e.g.: a table or a list), narrowing down the inner elements using LiquidMetal, which is way better than whatever else you could come up with.