A few days ago I had to break up a large stl file. This wasn't hard to do in blender (edit mode> select all> press p and separate 'by loose parts'). But blender has no way to export each object as its own stl!! Now I wasn't going to export 90 different files by hand, so after cobbling together various bits of info I put together this script.
To use it you have to save the file with the parts in first, open the script in blenders text editor. Highlight all the parts you want to export and then run script. It will save the files in the same directory as the .blend file.