>Bruce -
>
>That's good advice, and more or less what I have here, except for, as I mentioned I thought my 15" was in 640x480 and it wasn't. Maybe you can clear up my confusion though about what to expect. Do the fonts (whatever size they are) on your 17" appear relatively larger on your 15"? If that's the case, then I'll need to account for that in the future (e.g. make the fonts on my 19" in development) a certain percentage smaller, so they look OK on the 640x480.

No, they're about the same relative size, usually. However, we've seen cases where different video drivers can cause different appearances, especially on laptops...Also, if you use any non-truetype fonts, or any unusual ones that the user may not have, you can have trouble. Are yours all common, like Arial?