Keep a folder for any handouts issued during a course.

You can also use cassette tapes, radio, and television broadcasts.

These can be viewed or replayed whilst you are doing some other form of work.

Audio tapes can be played in cars, or on personal stereo systems.

Keep a dictionary, reference works, or any other data close to hand.

If you find something useful on the Internet, keep a copy on disk - or print out the page.