If your characters use only the standard morphs, then you can save the morph settings of the characters only by using one of the "Create Morphs Pose File" python scripts in freestuff (if you have ProPack or Poser5). Otherwise you can create pose file by hand. This by far is the most efficient way of storing charactres. You can also make your .cr2's smaller by setting the 'compress" option (also only ProPack or Poser5). This compresses the .cr2's during saving so they take up less space. You could also zip your .cr2's smaller using winzip or pkzip.