A keyloger would (normally) only let you capture the input from the keyboard, not what was being done with the mouse or what is being viewed on the screen.
There are plenty of remote control applications that although are more designed to let you control a computer remotely just like you were sitting in front of it most of the ones I've seen/used will let you run them in view only mode so the main computers keyboard and mouse inputs are not sent to the remote computer, this would let you see what was being displayed on the remote computers screen real time (though most will also warn/inform the person at the remote computer they are being watched, you may be able to disable this but I've never needed to so have never tried)
VNC is one such package that I have used and can recommend, but there are others
http://www.realvnc.com/index.html