today, I saw something that I want to create in the past.
a cluster system which requires no installation, no harddisk.
only a cdrom pop into PCs, then it works as one clustered system.
so it can easily work in pc labs in school. :p

It called clusterknoppix

and it's better!
client nodes doesn't even need CDROM! (when boot from PXE chips [rom])
or a floppy disk