I'm trying to design a resolution-independent GUI, and as such I'd like an exhaustive list of all possible screen resolutions. The ones I know about:

640x480 (Not used in XP; I'm mostly ignoring it)
800x600
1024x768
1152x864
1280x1024
1600x1200

What resolutions am I missing?

Also, what are the resolutions for widescreen monitors, and how do they look? In other words, if I draw a box 100 pixels wide and 100 pixels high, will it look like a square or a rectangle? Also for widescreen monitors, is TwipsPerPixelX = TwipsPerPixelY?

Thanks much.