Well, I'm not gay, but I'll answer anyway. ;) I generally shut off my Mac at night, so I set my computer to turn itself on first thing in the morning, and I changed the cron jobs to run the periodic daily, periodic weekly, and periodic monthly scripts after the computer wakes in the morning.
I repair permissions before and after system and software updates.
I run fsck when I'm having problems.
I occasionally run cocktail, onyx or panther cache cleaner, usually between projects, when I'm looking to waste a little time.
That's pretty much it. G5s don't need need a lot of babying.