Also refine the output calculation so you can input 4:3 resolution and get anamorphic output with borders on the sides instead of cropping the top/bottom, for when you want to create a 100% widescreen DVD - it's a slight annoyance having to change the aspect ratio on my tv viewing some DVDs when viewing the bonus extras.
Just occured to me, could add HD resolution calculation, but I don't know the resolutions involved.