I want to create an unprivileged user to run my RhodeCode server and Celery daemon on a CentOS instance.  I think the accepted definition of this is no home directory, login disabled, and no shell access?  Looking over the man page for adduser I just don't see an intuitive method for doing this.  Any suggestions are appreciated.  Thanks.
How to create an unprivileged user in CentOS?
centos;users;init script;privileges
From here (centos.org) useradd (which is the actual binary the runs when you call adduser, it just behaves differently. See here about that.) has an flag -r which is documented as follows: -r   Create a system account with a UID less than 500 and without a home directoryWhich sounds like what you want to do.