The Student Information Processing Board (SIPB - pronounced "SIP-bee") is an organization at the MassachusettsInstituteOfTechnology.
One fascinating claim to fame is that up until a short time after this WikiPage was created on October 10th, A.D. 1999, it held a stranglehold on http://www.mit.edu, while the "official" MIT home page was relegated to http://web.mit.edu. This was interesting because it was reversed from common convention. A WorldWideWeb page on the InterNet typically has a URL starting with www, while pages on IntraNets start with web.
As another aside, the MitMap can be visited at
http://whereis.mit.edu/doc/overview.html#printing
or
http://whereis.mit.edu/
(1999/11/03) A Google search turned up a reference to http://sipb.mit.edu/. It has "a brief list of other sites that you may have been looking for", including an entry for the SIPB homepage: http://www.mit.edu/sipb/sipb.html.