The Friends module takes you a step further towards Social Networking for your website. It allows your users to create and manage lists of friends just like Facebook. Aside from the typical friend request/confirm method, some alternate usages might be to follow other members, only allow "friends" to view your full profile, "bookmark" your favorite authors and subscribe to their channel entries, etc.
Along with Facebook-esque friends functionality, Friends includes complete private messaging (which works off of native EE private messaging), status updates, comment walls, "hugging", website invites and referral tracking system, and virtual groups where users can create and join groups. In combination with the User addon, the possibilities are endless.
Finally, a better way to make friends.