From West Valley Technical Services:
Never pay a monthly fee to monitor Internet connectivity again. ICM comes in two two versions: Free and Full. The Free version will allow a user to monitor up to 3 separate customer or internal addresses, and send a notification email if an issue is detected. The ping interval can be configured as low as every 30 seconds. It has a minimal footprint, as it runs from the system tray and uses less than 20MB of RAM. Perfect for IT contractors who want to stay on top of their customers' Internet connectivity.