I'm slowly getting more and more PCs from anywhere and everywhere, and I intend to cluster them all.

Which solutions does the forum think will work the best for this kind of thing? I have looked at LinuxPMI(OpenMosix), which I quite liked the concept of, and Kerrighed, but I think they're quite out of date as their latest kernel patch was around 2.6.20.

What are more elegant (don't have to recompile the kernel, maybe adding a module is OK, readily available in ubuntu package manager) solutions?