Set::Partition takes a list or hash of elements and a list numbers that 
represent the sizes of the partitions into which the list of elements 
should be arranged.

The resulting object can then be used as an iterator which returns a 
reference to an array of lists, that represents the original list arranged 
according to the given partitioning. All possible arrangements are 
returned, and the object returns undef when the entire combination space 
has been exhausted.

WWW: http://search.cpan.org/dist/Set-Partition
Author: David Landgren (http://www.landgren.net/perl/)