Tight VNC LAN Viewer

This software is great for Remote Assistance/Control over the LAN.
Its really painless to install and very quick.
       
STEPS

1. Download & Install VNC server on client PC from www.tightvnc.com/
   TightVNC
2. Install VNC viewer on Admin PC
3. Run the program and put in required IP Addresses of client pc's.
4. Then view user-activity

This software is great for remote-assistance is works better than remote desktop in some instances.

If you happen to be in need of monitoring client pc/workstations I would recommend it.

SCREENSHOTS