When a contact goes offline bring them to the top of the contact list

From MDLWiki

[edit] Explanation

On a non-altered WLM (Windows Live Messenger) Contacts List, the contacts you have are alphabetically ordered (the online contacts and offline contacts separately) in each group.

By using this function, you will overrule this ordering and make Messenger Discovery put the contact who logged off the last at the top of the offline contacts in each group. This way you can easily see who logged off last and who logged off earlier (the further down you go, the earlier the contacts have logged off).

[edit] Location

You can turn the function on and off in Settings > Windows Live Messenger > General Settings, as shown in the picture. It's the fifth box (second check box).