Sergey Biryukov

Checks via Google Search if the comment being left is a common spam comment.
Inspired by <a href="http://alexking.org/projects/wordpress" rel="nofollow ugc">Delink Comment Author</a> plugin from Alex King.

Unique Comments

Checks via Google Search if the comment being left is a common spam comment.

ckchaudhary

Extend BuddyPress’ private message feature by enabling attachments. This plugin enables users to send attachments in private messages. The type of file types allowed and maximum size of the attachment can be controlled by admin.

BuddyPress Message Attachment

Send attachments with private messages in BuddyPress!

Unique Comments vs BuddyPress Message Attachment