I was showing a friend of mine Ubuntu last night, and he was astonished that something so complete and useable was out there, and said "Why haven't I (a normal computer user) heard of this?"
"Well, there's no advertising.", I said. Which brings up the question, does open source telephony need advertising? Is Digium(R)Asterisk advertising enough? Would it do any good to run a local ad campaign targeting IT & executives?