I have two OS X machines that are "sharing" each other right now. I want to use emacs rather than finder to browse one machine from the other. How do I do this?
To access both machines from each other using a uniform syntax, then use TRAMP. For example, to open DIRED buffer on the remote machine:
C-x C-f /ssh:hostname:/path/to/folder RET
where you can replace hostname with its IP, DNS name, or local Apple name such as hostname.local.
You can use the same syntax to open a file directly:
C-x C-f /ssh:hostname:/path/to/folder/filename RET
Replace ssh with afp if that is how your local sharing is currently configured. TRAMP offers other protocols as well.
This syntax becomes handy when using emacs because you can use the same script to run from either machine. The path spec will pick up the same file/folder. You won't need separate programs for each machine.