In the Options menu, I see my graphics card, and a list of available resolutions. I click on one, but the 'Confirm' button is greyed out, clicking on it does nothing.
It's not a big deal, still enjoying the game, but I'd like to pick a widescreen resolution.
deanco

Same here :(

Ran into this problem...easy fix.
Go to your The Nations program folder and then to the tools folder. Inside you will find "setReg Trouble"" Run this and click on user defined under the resolution section.
Hope it works for ya.

Yeah, jamescarroll, I figured it out 15 min after I posted. You get a "SOLVED"!
In the Tools folder, I ran tools.exe, then Troubleshooting, which does the same thing.
Widescreen res, the text is too small anyway, I'm at 1152 now. Have not noticed any problems running at non-standard res.
deanco

Brilliant, thanks guys!

Another way should be to directly manipulate the resolution in the registry: Here's the key for Windows XP:
Change these to what you'd like to have. Note that the values are hexadecimal and setting wrong resolutions may damage your monitor. Try at your own risk!

Try playing on Linux under Wine.