There are literally hundreds of opportunities for internships. This page contains links to major specific web sites, as well as listings of some of the more well-known programs and opportunities that exist in each. Some of the most helpful resources will be those you were not looking for, so take some time and view other faculty recourse. You may uncover opportunities you had not considered or better yet, find that perfect match for your current interests.
Resource links have been gathered for some departments (others will be added as developed):