.. or nagios 
is great, I use it a lot.
In my continuing quest to cure command line phobia I’ve written a small (& Basic) php script that can generate some sample configs. Simply type in the IP of what you want to monitor , tick a couple of boxes, and copy & paste what you get into the end of your config files – nice 
There’s a Demo Site here : http://www.linickx.com/index.php?content=nagios
and the Source here: http://www.linickx.com/files/php/nagios-simple-gen_php.txt
UPDATE:
Also available at nagiosexchange.org: http://www.nagiosexchange.org/Configuration.20.0.html?&tx_netnagext_pi1[p_view]=327