[Rowlff]

I use PHP 5's built in SQLite as a database (which is the reason I didn't go with the more widespread Version 4).
That gives me full SQL capabilities without having to install anything else...

And yes to your other question: The cron job will just have to call a 'runhost' script every hour (or whatever 'granularity' of schedule you prefer), and this automatically determines the games that are due for a host and runs them!