pathartl

Accordion Archive Widget is exactly what the name implies. It recreates the stock archive widget, but this time around the widget is laid out as an accordion. It gives you the years of the archive, and then when the year is clicked it expands to show the months.
Development can be tracked at http://github.com/pathartl/accordion-archive-widget

Accordion Archive Widget

An archive widget that reconstructs the stock widget into an accordion by year with month children.

azurecurve

The Posts Archive plugin is based on the <a href="http://planetozh.com/blog/my-projects/ozh-tweet-archive-theme-for-wordpress/" rel="nofollow ugc">Ozh Tweet Archive – a theme for WordPress</a>. The tweet archive was extracted, enhanced and turned into this plugin which lets the posts archive to be displayed in a page or in a widget.
This plugin supports language translations. If you want to translate this plugin please sent the .po and .mo files to wordpress.translations@azurecurve.co.uk for inclusion in the next version (full credit will be given). The .pot fie is in the languages folder of the plugin and can also be downloaded from the plugin page on http://development.azurecurve.co.uk.

azurecurve Posts Archive

Posts Archive (multi-site compatible) based on Ozh Tweet Archive Theme; archive can be displayed in a widget, post or page.

Accordion Archive Widget vs azurecurve Posts Archive