asterisk users - Mar 2005 - Using Asterisk as VMail server on CCM 3.3.3 System

I've started to look at how I might go about using the Voicemail
functionality of Asterisk in our Call Manager environment we have in
the office.  We're currently using Unity but want to look at moving
off that if at all possible.

I've read a few things on the wiki and also taken a look through the
mailing list to see what info is out there to do this kind of setup,
but also wanted to put a call out to anyone who may have accomplished
this kind of setup and would be willing to share some info.
>From what I've read so far, a H323 trunk between * and CCM is the way
to interconnect the two systems.  There's been mention of having a
H323 Gatekeeper in the mix somewhere but I haven't had much chance to
take a look at this further on how this might hang together.  We're
not really looking to upgrade to CCM4 in the near future so SIP Trunks
are kind of out of the Q.

If anyone has any suggestions on where I might start reading up, or
can pass on their experience I'd be very much appreciative.  Would the
setup I've mentioned with a H323 trunk  be considered as ready for use
in production today?

TIA

Nathan