User Activity Real-Time Monitoringhttp://www.pttk.ae.krakow.pl/~mike/#whowatch
Whowatch is an interactive who-like program that displays information about the
users currently logged on to the machine, in real time. Besides standard
informations (login name, tty, host, user's process), the type of the
connection (ie. telnet or ssh) is shown. You can toggle display between users'
command or idle time. You can watch processes tree, navigate in it and send INT
and KILL signals.