batch resize

I like the fact that you can batch convert from one type to another (such as BMP to JPG) - it would be nice if there were some option for creating multiple size/densities, also, such as checkboxes for: create thumbnail for web, create web size/density, create email size/density, etc.

I assume one must still individually select which ones they want to process. Command line options for these conversions would be nice also.