Any suggestions on how to do directory operations, such as cp, mv, rm and 
so on, in a platform neutral way?

Obviously, system "..." will work, but then you have to test for OS.

I tried File.copy on a directory, but, as expected, that failed. (Returned 
false, but *also* left an empty file with the same name as the source dir 
at the destination. Is this a bug?)

Is the tree walker posted recently the best approach?

Maybe there should be a dtools.rb which adds this kind of functionality to 
Dir?

Thanks for any suggestions!

Joel