Just added a web server uptime monitoring in tinymailto.com
The service is provided for free by http://host-tracker.com/
Is really an usefull site, so I recommend it. It has monitoring rate up to 1 minute, and reports from dially to anual basis.
A few days ago it seems that all Internet in my country went down, I have another server on another ISP and suffered the same downtime in the same timeframe.
Hope it helps