lossless jpeg and png compression, maybe even GIF compression would be nice. these files need some crunching down. stuffit is capable of compressing these, so I know it can be done. it's just the HOW. I am sure there is some sort of software patent around for that or something or some.
winzip gives an algorithm,but it's copyrighted of course. maybe you can get permission to use it... http://www.winzip.com/wz_jpg_comp.pdf
or, maybe you can come up with your own. this is not my field by any means,but bug reporting is. this is now a common feature in compression programs.