Find Database Users

From: Ann (ao_949_at_hotmail.com)
Date: 01/08/05 

Date: Fri, 7 Jan 2005 16:32:38 -0800

I'm wondering if there is a way I can query against a
system table to find out all the users on a server and
what permissions they all have? If anyone has any ideas I
would really appreciate it! Thanks!