I had a post brewing in my head for a couple of weeks that was going to be titled “Keeping tabs on your crontabs,” inspired by some recent margins-of-the-day stuff I’d been doing. However, Peter Z at the MySQL Performance Blog has beaten me to it. I still maintain my title idea was better 
Check it out, it has some nice, easy-to-implement tips for making sure your crons don’t do stupid things and making your ops team happy (and we’re all about that at Flickr).