BuddyPress Global Search is a plugin that can create a unified search facility for your entire BuddyPress site, adding all the BuddyPress components into the search if desired. It extends the functionality of the existing site search.
Content Aware Sidebars is a WordPress plugin that allows you to create page specific sidebars that replace or merge with the default theme sidebars. The plugin comes with built in support for BuddyPress pages. Content Aware Sidebars has been created for those sites that want to create a unique look on some or all pages by allowing for page specific sidebar content.
BP Activity Share is a plugin that allows users to share the activity updates of others, similar to how this can be done on Facebook.