Walked over to Quicknet today. Had a good conversation with Greg, Jonathan, and a consultant: Craig Southeren, who is one of the founders of the OpenH323 project.
OpenH323 looks pretty cool. Open source version of software that supports real standards. Standards in the true sense of the word. H323 is used in equipment/software from just about everyone!
Unfortunately, Asterisk, the pbx I had been working on has not had any real development to support H323, so I'll continue looking for better PBX software.
Tomorrow, I'm going to download and build the OpenH323 stack, should have some interesting technical tidbits then.