If you think about it, even event-based schedulers have to have some timing mechanism to run checks. You could very easily set up a perl (or even bash) script to check a given file for changes and email you said changes at a given interval, say every five minutes.
Currently I have something similar to this set up, for use in checking whether a particular server has had any ports opened or closed recently. I have a flat file with the results of the last nmap scan. I hold the new results in memory, and test against the old. If there are changes, replace the old with the new and email me a 'diff' output. That way you get a running log of what changes have been made, on a case-by-case basis.
Hopefully that will give you some ideas.