Since you are looking for something "cheap" and easy, you might not be interested in this but this is relatively "cheap" and extremely "easy". In addition to monitoring server availability, SysTrack will monitor application availability for the apps you choose. If you are not a 24x7 shop, it also alows you to exclude weekends, holidays, scheduled down-time, etc. so the availability numbers you report are accurate. SysTrack does much more than availability reporting: monitors user session activity, monitors applications & services, inventory, changes, memory leaks, alarms, etc. If you are interested in finding out more, please let me know.
Mike
kapski@yahoo.com