Here are a few example scripts, that attempt to produce accessible versions of popularly requested scripts. They are generally requested in the usenet group uk.net.web.authoring
They all have the principle that they "work" where script is disabled/not supported, and to use the script requires no modification of the script, so users just use HTML and CSS to provide the appearance and the script figures everthing else.
Picture Galleries generally have thumbnails which open a fullsize picture in a new window. New windows are generally frowned upon in accessibiltiy circles for a variety of reasons, I suggest an alternative hopefully more successful gallery.
"Tab" controls are a popular user interface that don't translate all that well to a web paradigm, other implementations are always complicated and do not degrade well in the situation where script is not supported. This example contains nothing within the page content at all other than a DIV with a classname of TAB, the script then constructs the tabs. This means that without the script the page still functions well.
Popup menus also often have accessibility problems, keyboard navigation and fixed sizes are often used. Here an alternative is suggested, again where the menus are created using script so that the menus are listed elsewhere on the page when scripting is not supported and only become popup menus if their functionality is available. Reasonable keyboard support is also provided.
A Light Map, is a map commonly found in towns in the UK which when you press a button next to a place name, a light on the map lights up to show where it is on the map, this was an attempt at duplicating that.