I wonder if one should count game consoles? I've got an xbox that's on the network...
My count came to over 5 without it though so it wouldn't scew my answer anyways
Quite a shock actually, I thought I had very few but there's the media centre PC, sun server, laptop running XP to provide network console access to it, another XP laptop and desktop, another XP laptop to handle queued file downloads etc (always on, always busy). Business laptop is home and used most evenings, If I'm on call my work laptop is home too. Then there's the xbox.
Loads more in bits of course
So that's 8 or (9 if you count the xbox). Would be 9 (or 10) but my fileserver is broken at the moment so doesn't count (around 9 drives too close together and relying on convection to keep it cool = pretty bad idea in hindsight).
Yeesh.