rule 2: write provocative emails. you never know what could come of them. it is rather simple to deduce the CEO of a company's email by looking at how the other email addresses that are available to the public are structured. for example, if the emails seem to be first initial last name (ie pat firstname.lastname@example.org), google the company, find the ceo's name, and just apply the formula. (Sydney)
The CEO is often times not the best entry point to an organization. There's a reason their emails are usually not listed - they've got bigger fish than unsolicited emails to fry. Additionally, this tip is too often abused in that idealists or young guns contact the Big Guns without knowing what that person is into. Depending on the specifics of your writing, it could almost be labeled a form of spam... and no normal human wants to be that guy.
So, sure, there is the off-chance that you hit an extraordinary soul and something grand comes from your email, but I wouldn't count on it, especially if you had to use some trickery and Google to get their contact info. I'd start with a different point of contact, or would start first trying to meet people in person, i.e. networking. Those are much higher leverage contacts and, I'd guess, much more worth your time. Let them first give you permission (you must earn it) to contact them, just like we as consumers request of producers.
Update: Another link for unsolicited communication.