You could enable the FTP server built into OS X and then connect to your own Mac using Yummy. Once connected you can navigate to the MAMP/WAMP root directory in the server list of your Mac, and your other copy on your Mac using the Mac listing.
Enable FTP Access in the Sharing panel of the System Preferences on Tiger, or in Leopard click the Options button in the Sharing panel when you have File Sharing selected, then enable the FTP option.
To connect to the server enter 127.0.0.1 in the Server field of the New Connection or Bookmark window and use your OS X name and password in the same fields.