WP-Geolocation

– Free WordPress plugin determines a visitor’s location based on their IP address. Find downloads, documentation, and developer’s blog.

WPtouch Pro

– Transforms a WordPress blog into an iPhone application-style theme. A detailed product comparison chart highlights differences between a free version and several premium packs.

Widgetifr.com

– Free online widget builder which modifies user PHP code to create a WordPress plugin.

WordPress Designpraxis

– Offers free plugins and custom development of new ones.

WordPress Plugin Resources

– A comprehensive list of resources related to plugins and plugin development.

WordPress Review Site Plugin

– Offers a premium plugin that allows to add star reviews to a blog.

WordPress e-Commerce

– Offers an e-commerce shopping cart plugin for products, services and digital downloads.

1 Flash Gallery

– Provides a comprehensive interface for managing photos and images through a set of admin pages. Site has a how-to section and offers variable pricing for different versions of the plugin.

Another Wordpress Classifieds Plugin

– Add classifieds to a Wordpress site or blog. Site offers documentation, a free support forum and premium add-ons for the plugin.

AutoBlogged

– WordPress plugin for automatically creating posts from an RSS or Atom feed.