Can you use the command line on a Mac to get to a networked Mac?
Use the mount command to show the various mounted shares. You'll see something like this:

$ mount

//GUEST:@betafat/tmp on /Volumes/tmp (smbfs, nodev, nosuid, ...
afp_0h2ueA0008BK0000oM0000VU-2.2e000005 on /Volumes/admin (afpfs, nodev, nosuid, ...


The first line is a Windows SMB share from an XP computer, the second line is an AFP share from another Mac.

Note the mount points after the word 'on' above.
You can access the mounted shares using mount point just like you would any other directory, i.e. ls /Volumes/admin