Found this fairly annoying - only because I went through this exercise recently, and now all the research i did has been made redundant.

I bought this book to help me out:

http://www.amazon.com/Fair-Division-Cake-Cutting-Dispute-Res...

It's a great book, though it didn't include exactly what i was looking for regarding this subject. I emailed one of the authors and he kindly pointed me in the direction of Sperner's Lemma:

http://www.inet.tu-berlin.de/fileadmin/fg234_tdc1-s11/FDS_SS...

and I was able to find:

http://www.math.hmc.edu/~su/fairdivision/calc/

Which is the same sort of calculator...

Anyway same end result...though i highly recommend the book above if anyone is interested in the subject.

Fair division, the win-win solution, etc, also have some roots in the Nash equilibrium (a beautiful mind). Also known as adjusted winner: http://en.wikipedia.org/wiki/Adjusted_Winner_procedure

Fair division is really an algorithm based in game theory on fair distribution. There's actually a bit of software based on it... a couple examples:

http://portal.acm.org/citation.cfm?id=1352161 http://www.fairoutcomes.com/

and a patent: http://www.patentstorm.us/patents/5983205/description.html

I first read about it because of conflict resolution:http://www.amazon.ca/Fair-Division-Cake-Cutting-Dispute-Reso...

There's also some interesting analogies in OS, multi agent systems, and Database conflict resolution. But that's probably for another thread.