I have Photoshop CS3 and I need to do a batch on a lot of pictures before I upload them. The pictures need to fit in an 600x800 box, yet be as big as possible within that box.

Some of them are much wider than taller and others are more tall than wide. I am trying to put together a photoshop action that will rotate, resize, and fill pictures as needed to make them as big as possible while staying within the 600x800 box.

The only thing I haven't gotten sorted out is how to tell photoshop to rotate the image 90 degrees if that will allow the picture to be bigger within the constraints. Any ideas?