You can ignore a user so you don't see their activities, they still see you. Its like ignoring a person in a busy room.

FT's vb version allows you some privacy not to be seen if you enable the 'invisible mode' in the options: http://www.flyertalk.com/forum/profi...do=editoptions

That way all other users don't see if you are online, what forums you are currently viewing etc. Your profile still shows to every one who is interested to see it.