Haven't used it personally, as I and all friends use skype, for better encryption and more privacy. But the product has always had good reviews. It takes a bit of work to set it up, I presume you know this?
http://vochat.com/http://www.bartrade.biz/chat.htmhttp://www.siteground.com/voodoo_chat-hosting.htmHere is a fairly good comparison list of similar chat programs --
http://www.rocketdownload.com/scripts/query.php?q=voodoo+chat+room
