Desoxyn, there are some great audiobooks out there. I use bit torrent to get them for free. Audiobooks seem to be the most expensive medium i know besides online lectures.

I recommend doing something physical while you listen, like doing the dishes or mowing the lawn, or picking up around the house. The act of a mindless activity will let you forget about your body while you sharpen your mind. That's my trick to being attentive. But we're all different, i hope it works for you!