Centralizing Administration

Hi guys.
I work in an environment that caters to 150 + Solaris servers. I was wondering whether there is an application/Software that can be used to centralize Administration.
e.g. If a new member comes into the team , I am required to go onto every server and create his login. Is there a system that I can perform on a central main server that gets replicated onto all the servers on my network....
Making new usernames is just one of the tasks that I want done. Other tasks may include replication hosts file onto all systems by just editing one file.

So is there any such mechanism ?

Regards,
Junaid

a directory server (e.g. ldap) is a good way to start... or you can have a look at this:
Ops Center Focus Area