cluster-printers.mit.edu is the MIT-run server for the Common Unix Printing System, the native printing system on Apple and Ubuntu (in fact, Apple bought out CUPS, Inc. recently...).
To make your Mac print to cluster-printers.mit.edu, run the following commands at a Terminal:
echo BrowseProtocols cups | sudo tee -a /etc/cups/cupsd.conf echo BrowsePoll cluster-printers.mit.edu | sudo tee -a /etc/cups/cupsd.conf sudo launchctl stop org.cups.cupsd && sudo launchctl start org.cups.cupsd
You need to do this from an administrator account. Provide your login password when asked.
If you're using Mac OS X 10.4 Tiger, when you go to a print dialog, "Shared Printers" will pop out and list all the public cluster and dorm printers at MIT.
If you're using Mac OS X 10.5 Leopard, print queues aren't added automatically. If you go to System Preferences, choose Print & Fax, and select the "+" icon to add a new printer, all cluster and dorm printers on campus are listed under the "Default" tab at the top.