I've written a package for index handling which also includes sorting
of the index. It isn't finished yet, but since I'm quite busy right now
I decided to release it in its current state. If anyone is interested,
it can be found on my home page.

Things currently missing are:

 o merging of identical entries, i.e., you get

     foo, 17
     foo, 21

   instead of

     foo, 17, 21

 o documentation

 o There are still some issues with stack overflows.

 o Index entry formatting is rather basic.

 o There is no \index command right now.

                                                              | \_____/ |
   Achim Blumensath                                          \O/ \___/\ |
   Mathematische Grundlagen der Informatik                   =o=  \ /\ \|
   www-mgi.informatik.rwth-aachen.de/~blume                  /"\   o----|