Now now, don't jump to conclusions of it using the hard drive... Although I had never thought of that possibility before, and now that I think of it it kinda sounds like you'd need it...
I wonder how many hard drives it could push if it requires one
And yeah, I forgot all about trains that just go around one city and you can walk around in (and hijack and control like in GTA1)... But there should also be instant transport modes of transportation from one city to another for people too lazy to travel through the (what I hope to be) large countryside...