Caltech Library Services is happy to offer this new service.  When locating a book through the library catalog, you can now click on “Place request,” log in with your name and UID, and choose a Caltech Library to pick up the book.  A book is usually available for pick up after 1 business day.  This is a great service if you are requesting several books and want to pick them up in one convenient location.  However, if you need a book very quickly, the best method is still to come to that library and grab it.