One of our puppet rules ensures that NTP (which ensures that the server has the correct time) is not installed on any virtualised guest images where the time is supposed to be taken from the host automatically. Unfortunately "facter" which should provide this information still hasn't applied patches submitted over 6 months ago. So we've rolled our own package instead for use on Debian Lenny.

I'm often called paranoid, but really, it's a good thing. If you aren't paranoid, you aren't thinking hard enough. Computers require 100% correctness - if you miss one step or make one mistake the result can be catastrophic. You constantly have to think "what could go wrong", "what can I do to stop that happening", "if it still goes wrong, how can I fix it". Generally this means doing extra work up front which may never be used, however it's a wise insurance policy.