I saw this problem for the first time in the rec.puzzle newsgroup (in 1993 if I remember well).

The interested reader can have a look at the “Partition Problem” (http://en.wikipedia.org/wiki/Partition_problem). It is not the same problem but it mentions the above heuristics.

A local search procedure is described in

[codognet2001yet]
Philippe Codognet and Daniel Diaz
Yet another local search method for constraint solving
Stochastic Algorithms: Foundations and Applications, 73–90, 2001