GoDaddy’s VPS (running CentOS) is my production machine for all public web sites (too many, cannot list all of them here), and will be the server for running PHP/C/C++ based applications.
Ubuntu @ Shanghai home will be the primary machine for playing with Python, I’m going to spend some time on django.
Machine @ US home will be the machine for cluster testing, especially cloud-like stuffs like Cassandra, MongoDB, etc.
PowerBook will be retired soon (actually it is just lying down there without powered on), however, I will put Lisp related stuffs there to see how far I can go with Lisp.
I don’t have any further machines, and probably I don’t have time to take care of more.