Harvard students can cross register for courses at MIT. The following pages can be useful in how to do so:
You should also talk to your resident dean to make sure the process goes smoothly.
Some MIT courses can count towards the Computer Science concentration. This table lists some of these courses. If you want to petition for counting a course that is not listed in the table, email firstname.lastname@example.org with the syllabus of the course, any other information, and what requirement would you like it to count for (e.g., elective, breadth, theory, math, etc..).
A tip on getting to MIT: The LMA M2 shuttle is free with a Harvard ID. You can also use the T (red line), a bus or a hubway bike.