To monitor a server from anywhere using the Internet, you can use this php scripts: phpsysinfo. You only need to install it:
debian:~# apt-get install phpsysinfo
Then, open your browser, goto: www.yourdomain.com/phpsysinfo or your-ip-address/phpsysinfo.
There are several template and language supported. Even, Indonesian is there.
For security reason, rename the phpsysinfo to other unique name. This is not entirely secure but it is better than still using phpsysinfo name, for example: kuntul.
This is very useful scripts for a sys-admin.