I got SER up and running with a whopping total of three "domains" being served on the same server. It was mostly painless, if missing some features I'd like to have seen (more on that in later messages.)
What open source products are people using for voice mail, voice menu prompts (press 1 for sales, press 2 for the executative restroom) and for conference calls (which include PSTN calls as well as IP phones)?
--Michael