Well, if you count all the machines that all my clients use as one big network, and it's not inconceivable since most of them to link to each other in some ways, I've got almost 60 nodes on a network, not counting the 11 node network I have in my home right now.
Darn thing is, that even my relatively small network has lots of the goodies that larger networks use. 802.11b connectivity? Got it. VPN? Got it. Web and FTP services? Have them. Macs and PCs and Linux and Palms? Oh yes, cross platfrom is here. Is this a big LAN or small WAN? Well my clients span almost 300 miles, you decide