We all know that oftentimes taking notes
or listening alone are not the best use of your time in a lecture. If you subject yourself to the class, you might as well make the best of it
To Facilitate The Lecture
Bring your book to class. Many profs like to read verbatim from the text or will supplement their lecture with the test. Following along in the book and making notes in the book or in your notebook with pointers to the text will save you time from taking notes on what you will read. For those whose prof lectures material not found in the text: I pity you.
Dragging your books to class as a commuter student is a real pain, especially if you use public transportation. If there are no academic lockers on campus (they are usually found in the libraries), go rent a locker in the gym. They are usually pretty cheap (1/3 size locker: $8 / semster) and fairly secure. This also gives you an excuse to go exercise. A bookbag with wheels also eases your load.
The Lecture Is Boring
Isn't it, though? Do your homework for that class in the class. Do your homework for another class in the lecture. Lectures are one of the quietest places around, especially on a loud campus.
Catch up on correspondence. Honestly, there is nothing like a handwritten letter, and when you have upwards of 45 minutes to fritter away, what else should you do (we'll get to napping later)?
Balance your bank account. Yes, you really should have one, or be aiming to have one, at this point. Pull out your transaction register, your monthly bank statements, and your calculator, and go to it. There's nothing worse than a poor record of your finances when you get audited or when you have a dispute with the bank or your credit card company.
Know your napping etiquette. If you have a tendency to nap or if the prof's voice has an uncanny resemblance to that of Ben Stein's, be prepared. Sit in the back. Napping in the front of the lecture hall is plain rude. Give those seats to the people who can maintain consciousness for the whole class period. Have the proper napping apparatus. Soft books are a must. Usually a used textbook does this job quite nicely. The book must be large enough to rest your head on (trying opening it up to the middle of the text). I've found that math books are not a good choice in these matters. A sweater is even better. Try to minimize drooling and snoring and make sure you have someone nearby poke you five minutes before the class ends.
Get some exercise. I've also found that some lecture halls are conducive to discreet forms of exercise. If your classroom has swivel chairs mounted to a long table or the floor, you can work out your abs. Place your arms on the table at shoulder distance from each other (90 degrees from your body) and sit erect. While not moving your upper torso (shoulders, chest, neck, arms, head), use your abs to move the chair from side to side. Do this at a constant rhythm and not quickly (this usually catches someone's attention and is not healthy). Sit in the back if you are going to do this. If your lecture hall has stadium seating, you can also do some leg stretches. Make sure that no one is sitting directly in front of you. Raise your legs as if you were sitting on the ground and point your toes. Stretch and flex.
Unobtrusiveness is key
Good luck and enjoy.