I received an email telling me about another IP-PBX from a company based out of Belgium. Packetbox is a turn-key software and hardware solution based on a customized Linux operating system.. It's called Packetbox, a preinstalled appliance that contains anti-spam, anti-virus solutions, ipsec for vpn's, groupware and a customized Asterisk solution with web based interface and flash panel. It provides a Windows compatible domain controller for user authentication & management, file & printer sharing and DHCP & DNS services. You can find more information about it at http://www.packetbox.net
The device retails at around 1000 Euro.