We recently released Accordion Blocks module in dupal. This module applies the accordion effect for the blocks appearing left and right side. Just install the dependend modules and this module, the accordion effect will apply to the blocks. We can change the theme of the accordion widget by changing the theme at admin/settings/jquery_ui path. These themes can be downloaded from jquery ui theme roller . This module works with all standard drupal themes.
Demo of the accordion blocks module is avaiable at http://drupal.azrisolutions.com/accordion_blocks_demo