Barton, the MIT Libraries' Catalog
http://libraries.mit.edu/barton
Barton includes books and journal titles owned by all of the MIT Libraries. It does not list journal articles.
MIT's WorldCat
http://mit.worldcat.org
WorldCat includes books owned by libraries around the world. Use BLC Direct Borrowing, Borrow Direct, or Interlibrary Borrowing (ILB) to request delivery of books from other libraries to MIT.
Tozzer Library
http://hcl.harvard.edu/info/admittance/index.cfm#tozzer
A top anthropology and archaeology library, Harvard's Tozzer Library is open to MIT students. To check materials out, first get a Harvard College Library Special Borrowers Card.
HOLLIS
http://hollisclassic.harvard.edu/
Harvard's online catalog.