The easiest way I found to do this is to burn several clusterKNOPPIX CDs and boot them on several PCs on a LAN. This creates several nodes that can interoperate and already see eachother. Just run openmosixviewer in a shell to see all your nodes (from any of the nodes). BTW, I can't run LTSP because of a Wimpdoze DHCP server on the same LAN....
To test the automagical load balancing of the openMOSIX kernel, run Kandel from one node and watch the processes auto-migrate to other nodes on the openmosixviewer. The first time I tried this with clusterKNOPPIX it actually did not work. I've been using Quantian that's based on clusterKNOPPIX lately and it works fine!
I've had up to 25 nodes each running a PIV 2.6 GHz with about 800MB RAM each. Thats like one PC running a 65GHz processor with 20GB RAM!