Memory usage under OS X PB


I recently upgraded my G4/500 SP from 256 to 768 Megabytes of RAM (hey, RAM is dirt cheap these days; when it gets under 200 bucks for 512 MB I'll probably upgrade to 1,280 Meg). With 256 Meg of physical RAM, OS X liked to slurp it all up, maybe leaving 2-5 Meg free. But even with every application I own running, including a bunch of big Classic apps like Photoshop, OS X never seems to need more than about 600 Meg, leaving more than 150 Meg free, and usually more like 250-300 Meg free. Does this mean I can have 40 or 50 apps open at once and still not run out of physical RAM? I've noticed that there's hardly any paging out to the hard disk, and in fact Top says there are zero pageouts. Seems like if nothing else it should save a lot of wear and tear on the HD…