OSX Leopard: What is the /home directory for?

What is the /home directory in OSX 10.5 for? It appears to be:

1. Empty.
2. Created or last modified when the machine last booted up, with user.group of root.wheel (this differs from /Users which is root.admin).
   
3. Impossible to copy to, even as root. You just get "Input/output error".

I was trying to change the default user home directory location on my Macbook from /Users/<username> to /home/<username>, so as match Linux and simply rsyncing between my linux boxes and the macbook, using one of the following methods described on macosxhints (1 , 2 ). (They were not trying to use /home but move the home directories to a separate volume.)

I can't find any mention of "/home" and OSX anywhere on the web, and leaving off the / just gives articles talking about /Users/. BSD seems to use /home (just like a sensible *nix), so I doubt its a BSD versus Linux thing.