Anchorify.js (GitHub: willdurand / anchorify.js, License: MIT) by William Durand automatically inserts unique anchored headings. The default markup is an anchor with a pilcrow sign, but this can be overridden if desired.
Even though the plugin is relatively simple, William has included QUnit tests and put the project up on jQuery's new plugin site.
Minimalect (GitHub: groenroos / minimalect, License: MIT) by Oskari Groenroos is a
select element replacement that supports optgroups, searching, keyboard navigation, and themes. It comes with two themes that are intentionally simple, allowing you to easily customise them using CSS, and no images are required by default.
Options include placeholder text, a message when no search results are found, class name overrides, and lifecycle callbacks.