I wrote this little guide for myself, preparing the arrival of my Dell 2005FPW and of course tweaks for games with proper aspect ratio. The easiest way to use this is pick the RESOLUTION for your game and follow the formula. Also copying and pasting this to NOTEPAD with MONOSPACED fonts will make it more READ-ABLE =)
I hope it helps people out. And for the record 1280x768 is 16:9.6 Aspect Ratio according to my calculations. Please don't bash me if any information is wrong. I'll correct them if proven wrong.