What's Greek for Alma Mater?
There is a nice new(ish) alumni community site.
Advanced Book Exchange - used, new, old, out-of-print. Thousands of bookstores at your fingertips. Very dangerous.
Scholar's Bookshelf - new, many heavily discounted books in history, literature, arts, religion, philosophy and baseball. Doesn't always have what they say they have. Often has free shipping specials.
Alibris - haven't bought anything from them in years, so can't offer any comment.
Labyrinth Books - scholarly and university press books. Huge sale annex offers deep discounts.
Daedalus Books - remaindered and overstocked books and CDs.
Dover Publications - inexpensive classics, children's books, art, music, science and math texts.
Green Lion Press - publishing original source texts in the history of science and history of mathematics and run by two alumni/former tutors: Dana Densmore (A65) and William H. Donahue (A67).