384...
...works great for what I do (typing, internet, light 3d work, photoshop, mail, a little programming, etc... when I type vm_stat in terminal it always says 0 pageouts). I suppose if you run a *lot* of apps at once, or mess with 1200dpi photoshop documents you would need more. Anyway, OSX is awesome. It has some flaws (what doesn't), but overall it's awesome.