To add to that, I'll just say that Leopard Server makes remote time machine backups a piece of cake.
I have a designated 1TB time machine drive in my Xserve. The first time I power on a computer with Leopard with the server on line, "the magic happens" and it sets everything up automatically.
As I said, the $90 I paid for a copy of Leopard Server was worth every penny of it.