You can put the password/username in a text file, and have smbmount check that file for the login info (use the "credentials" option). Change the permissions of the file to 400 or 600 so that only root can read/write to it.
Attention: ;)400 or 600 does not mean, that only root can read/write it. It means that the user can read/write it. That can be a critical factor, if more than one person are logging in with this account. May be that not all persons should know about the smb account password.
