Suggestions For Application Which Simlplifies Scanning 4x6 Pictures

Hello everyone,
I have hundreds of 4x6 photos from back in the "film camera days". I would like to use my flat bed scanner to scan them into JPEG files. Are there any suggestions/applications to simply this process?

Currently I'm scanning 4 at a time and cropping them into individual images but as you can imagine, becomes tedious after a while.

Thanks for any feedback.

I did the same with a smaller number of pictures (about 30). I still did scanning & cropping manually, but I found one good GIMP plugin was Deskew (http://www.cubewano.org/gimp-deskew-plugin/). Contrary to its description, it will straighten out almost any graphic image where an edge is slightly off horizontal.