samba - Jan 2005 - Other users to be able to write to a filesystem besides root

I have a filesystem mounted as such...
 
//machine/share /mnt/machine/share smbfs
credentials=/somedir/passwordfile/username,rw,user 0 0
 
When I'm logged in as root I can rw that filesystem perfectly fine.
 
When I'm logged in as another user, I want the same ability... but am
getting Permission denied errors... how can I let the other user also write
to the file system?