asterisk users - Jan 2005 - Asterisk + SER Questions

I'm trying to setup a PBX with Asterisk and the SIP Express Router.
Asterisk will handle PSTN incoming and outgoing calls, voicemail and
conference rooms, while SER needs to handle SIP registration and SIP
to SIP calls while forwarding requests for other features to the
Asterisk box.

Does anyone have any good examples of using Asterisk and SER together? 

Thanks in advance.