Has anyone used a free conferencing solution for conference calls?

I'm looking at a free or low cost option for hosting conference calls within our stake. I've had a look at free services such as freeconference.com, freeconferencecall.com and freeconferencecalling.com, and they look and function well. Their business model sounds fine, but I'm interested to know if anyone out there has had any experience with them, good or bad.

We've used freeconferencecall.com and it seemed to work fine. It was a long distance call, but our buildings have free long distance, so it didn't matter. My wife used it for stake girl's camp meetings a couple of years ago and they each just called from cell phones after 9:00pm when they all had free talk time.

edit: I just noticed that you are in Australia, so I don't know if my experience applies at all or not.