upping screen resolution

[Duncan Lithgow]

Why is it that I can't crank my screen resolution above the screen's
native pixel dimensions? I did this on Fedora, Suse and Windows2000.

I have good eyes and good lighting conditions, and work a fair bit with
graphics, so a 'bigger' perceived screen size would be great. So I'm
left with two questions:

1. Anyone know what I can do about this?
2. Why doesn't gnome support a few sizes above the screen's preferred
one?

Duncan