This is really a valuable source though, and not only for academic positions. Check it regularly, as it comes out weekly. The Chronicle of Higher Education . It is interdisciplinary. The Times Higher Education Supplement .
Most British universities advertise here.
Some British universities, particularly Oxford and LSE, and several universities from the Commonwealth prefer this weekly to advertise vacancies for Lectureships, Readerships, or Fellowships of all sorts. They have an excellent archive. Room 133S, Simcoe Hall, King s College Circle. The School of Graduate Studies has a very good database. This web site gives access to the Community of Science database, which offers a comprehensive list of research grants, fellowships and research positions in the USA and Canada, as well as overseas.