OpenBSD are doing great here. In one year we have installed more than 40 servers running FreeBSD and have more than 300 satisfied customers. Now I have almost 200 users in 8 buildings. The FreeBSD boxes have no keyboards or video boards. The buildings near each other are linked by 2 wire modems and the ones farther out are linked by wireless LAN at 3MB bandwidth.
Email is routed to the server nearest the client using sendmail.
There are 15 Boxes in the network administrated by two persons. The cost to setup the whole network has been very low, and it has been delivering good performance thanks to the squid proxies on each FreeBSD server. Some people said I was crazy. Now I am selling FreeBSD to the clients of those people. Thanks to the FreeBSD Team.