BuddyPress Classifieds is a plugin by G.Breant that adds classifieds ad components fully integrated into BuddyPress.
Features :
Write your ad directly from the frontend, WYSIWYG
Allow/disallow moderation
Browse by category, tags, …
Breadcrumbs
Add to favorites (“follow)
Upload pictures with your classified
Link classifieds to groups
Define a map (Google map) to locate your classified (powered by BuddyPress Maps)
Download and info: http://wordpress.org/extend/plugins/buddypress-classifieds/