If all you want to do is ping some hosts on a regular basis, then sure it'll be easy to whip something up fairly quickly. But if you want a decent Network Monitoring System, then you're better off going for something out of the box. My personal favourite is Big Brother. It's open source (although there is a commercial version available), well supported and dead easy to get up and running quickly. As well as all the standard NM tests that come with it (including ping), it's fairly trivial to write your own customised plug-ins (in Perl, of course :D). I'm currently using it to monitor around 600 separate hosts worldwide, and it works like a dream :)

Nagios is another Open Source NMS that is highly considered. I've not used it, but I do understand that it is a cow to get configured.

Hope this helps,
Darren :)