Looking out at the students in my introductory physics class, it always struck me as odd how many had tape recorders sitting on their desks.  Occasionally I'd inquire about them - some students recorded lecture as a form of note taking, others were recording for a friend who was absent, and still others were not native English speakers and wanted to re-listen in order to better understand (the language not the physics).  It was obvious that many students wanted and needed lecture recordings, but this "solution" was far from optimal.  Surely it was redundant to have so many students recording the same thing.  Certainly the sound quality was poor given that I spent a fair amount of time facing away from the students while writing on the board, and the opportunity for students to listen to a missed lecture would only be available if the student knew in advance that they would be missing and could have a classmate record the lecture for them.  It is for these reasons that I began to record my lectures and distribute them as podcasts.  Initially I used the built in microphone eon my computer to record the audio, which I would then publish as a podcast.  This was an easy solution that added little overhead to my workload, and cost me nothing.  Student response was tremendously positive - many students told me how much they appreciated this.  Perhaps it was the recordings, or the act of a faculty member reaching out unsolicited towards the students, or a bit of both that they appreciated.  

Over the next year I began to expand my repertoire of tools for podcasting.  I purchased a wireless lapel microphone that would allow me to record much higher quality audio that did not have level changes as I turned towards the board to write.  I discovered a software program called "ProfCast" that allowed the slides from my presentation to be captured and synchronized as a slideshow with the recorded audio.  Despite these additions, I found the workload associated with podcasting my lectures remained minimal, but the student response became even more positive.  Based on my class surveys, most students used the podcast at least once during the semester, and they felt much more connected to the class than they had been.  In particular students who missed class reported having a much easier time to "catch up".  

I've podcast class lectures for several years now, and routinely poll the students about their opinions of the podcasts and its affect on their habits.  Of over 200 students, only one reported that she chose not to attend class because of the availability of the podcasts.  When asking students to assess the value of the class lectures, the textbook, office hours, the podcasts, and the class homework, students ranked the value of the podcasts well ahead of that of the textbook or homework problems, and only slightly below that of the actual class lecture and office hours. 

Beyond the value to the students of having the lecture recordings available, I have found the recordings from previous semesters tremendously useful when reviewing material in preparation to give a lecture.  Particularly in my graduate level classes it often takes several hours of my time to review the textbook to bring myself "up-to-speed" with what I was trying to convey in my lecture notes.  By listening to the podcast, I can much more quickly recall the details of the lecture.  Additionally I have used recordings from precious semesters in place of a class meeting on occasions where I was traveling and would otherwise have had to cancel class.  I even used previous recorded lectures as a way to supplement classes this year that were shortened due to faculty furloughs.  

Through the "Technology and the Classroom" Faculty Learning Community, I've learned about many other ways faculty are making similar  investments in technology that benefit both students and themselves, such as providing recorded feedback to students or streaming lectures live.  Combined with my personal experience it is clear that technology can be used effectively to engage students without overburdening the instructor, and in many instances can even reduce the instructor's workload in the long term, while improving the learning environment for the students.