Dug Song provides the source code for Monkey.org's systrace shell wrapper. It is used to systrace all user accounts on Monkey.org from the login shell. See his post for more information.
Michael Lucas posted an introductory article on creating policies for Systrace. He gives a brief overview on how system calls work and then goes into explaining the Systrace policy creation for named. If you are a new to Systrace this is a good article to read.