I have posted this idea before and many liked it, and I would like for it to be incorporated into v9/v10. So...
I think it would be cool if for version <VERSION HERE> of Blockland had a friend/enemy list, you would send people friend request and if they accept they get added to your friends list, from there you can click on their name and click find, and it will tell you what server their on, or if their browsing, if they are logged off, their name would be grayed out. If someone is on your ignore list (they don't get notified) it will warn you if you are going on a server their on and they cant go on your servers.