In addition to all of the scripts and techniques for running mprime across a network of workstations, I'd like to point out condor (http://www.cs.wisc.edu/condor/) which will do cross-machine migration of processes, provide checkpointing services, and allow you to configure when processes are started/removed very flexibaly. (ie, you can start/stop them based on load average, numbers of users, the idle time of the machine, etc).
