How can I mount an SMB share from the command line?
You could easily achieve this using mount_smbfs (which is, actually, a wrapper for mount -t smbfs) : 

mount_smbfs //user@SERVER/folder ./mntpoint


Optionally, add the workgroup :

mount_smbfs -W workgroup //user@SERVER/folder ./mntpoint


You could, of course, change the ./mntpoint (for something like /Volumes/smb).

After doing this, simply go to ./mntpoint to browse your data.

To unmount, using the following command : 

umount ./mntpoint