I started my MBA program hoping to record most lectures using a digital voice recorder. My plan was to review lectures during my commute to work or class. For my Organizational Behavior class (MBA860), the recordings were invaluable (Thanks to Prof. Ford for his permission) . This is especially true when the professor does not use or make available his lecture notes.
This quarter, however, I am not using the voice recorder. In MBA870 Data Analysis, the class is primarily based on in-class laptop/Excel work in which recordings would not nearly be as useful. My other class, MBA825 Enhancing Professional Exchange (Speech), does have several lecture days however the professor preferred that students not taped his lectures. I fully understand his reasons for such, though it sure is nice to have the lecture recordings available in case I have to miss class for business travel or sickness.
Always ask permission first before recording the lectures.
When recording, try to sit close to the professor so the recordings are clear.
If you bother recording lectures, then listen to them! Recordings demand some extra attention in order to classify, sort, save, and burn CD's.