You can add "friends" so you can easily get to their puzzle collections.
This new feature expands on the previous feature that showed a list of people you have traded with. Now you can make friend connections with other people and quickly access them and their collections.
To add a friend, visit someone's profile and click the "Friend" button under their profile picture. If you have been invited to be a friend, you can accept or reject friend requests either from the person't profile page, or from your friends list page.
Friends that are online show at the start of your friends list page.
As an added bonus, you can view puzzles offered by your friends all on one search screen. There is a link on the friends list screen.