If you are not tied to the idea of having Perl handling the actual inter process communication, there may another option that might prove useful: openMosix. Here's some text from the web site that best describes what it does:

"…openMosix is a Linux kernel extension for single-system image clustering. This kernel extension turns a network of ordinary IA-32 computers into a supercomputer for Linux applications…."

"…There is no need to program applications specifically for openMosix. Since all openMosix extensions are inside the kernel, every Linux application automatically and transparently benefits from the distributed computing concept of openMosix. The cluster behaves much as does a Symmetric Multi-Processor, but this solution scales to well over a thousand nodes which can themselves be SMPs."

In theory, all you need to do is write your Perl code so that it forks off a process to do the number crunching and then return the data when it finishes, the kernel patch will take care of locating and moving the thread to an available machine for you. Processing nodes can be added or removed from a cluster without requiring effecting running processes (other than speed). The only down side to this is that this only works with Intel compatible processors and Linux, so this can't be run on a Sun box. However, it is FREE, and may be able to improve the performance of your existing Perl code with little or no modification.

More info can be found on the web site here: http://openmosix.sourceforge.net/

Rick