Last week I gave a couple of lectures at the University of Michigan.  I tried to connect to their wireless network, but I was challenged for a U-M ID.  I was told that all I needed to do was plug the Ethernet cable on the tech cart into my computer.  Wired connections in classrooms at U-M get a DHCP address without challenge.
 
So this is actually pretty funny: at MSU we give out free guest access over wireless, but not if wired.  At U-M it's the opposite.
 
This has consequences.  A few years ago at the Usability and Accessibility conference, one speaker went to give his talk based on live reviews of Web sites.  His laptop for whatever reason wouldn't connect via Wi-Fi.  He was saved only when someone in the audience offerred up his own laptop.
 
This person was only 10 feet away from an Ethernet outlet, but he didn't plug in because Kellogg Center employees didn't like the hassle of having to cough up their own MSUnet ID and password.
 
I think MSUnet Wireless Guest is not only a great idea -- it may be unique at major universities.  The world did not fall apart when it was opened.  So now imagine if we combine MSUnet Wireless Guest with open access if you plug into an Ethernet jack in a classroom or conference room.  Ann Arbor didn't fall apart when I plugged my laptop in.
 
/rich