if you ever desided to make dragging and dropping contacts from the messenger window to the desktop and vice versa, one suggestion to make this process less confusing would be this:
when dragging a contact from the desktop, back into messenger (to take the contact off the desktop) have it so u can just drag that contact anywheres onto the screen and it simply hides (removes) the desktop feature for that contact. dont have it so when u drag them back into messenger u have to arrange them back into the special groups and move them all around etc... like msn messenger does without plus
hopefully you know what i mean