Taking notes is so old school, especially given all the readily-available methods for recording lectures. While your cell phone will work well for audio and video recording, you can really kick things up a notch with the Olympus LS-20M recorder.
It captures super high-quality audio and full 1080p HD video. The best part is that the camera lens is actually on the top of the device, so just place it unobtrusively on your desk and hit the record button.
Voila! Studying has now become as easy as watching TV.
Link: Olympus LS-20M