WP Get allows you to display content in posts dynamically, depending on URL parameters.
AddThis allows any visitor to bookmark and share your site easily with many popular services.
Benchmark Email Lite creates a newsletter signup form widget.
jQuery Vertical Accordion Menu creates vertical accordion menus from any WordPress custom menu.
W3 Total Cache allows you to improve site performance and user experience via caching.
WPtouch automatically transforms your WordPress blog into an iPhone application-style theme, complete with ajax loading articles and effects, when viewed from an iPhone, iPod touch, Android, Opera Mini, Palm Pre, Samsung touch and BlackBerry Storm/Torch mobile devices.