Something I do, if I'm really busy and have a thick 20+ chapter book that's highly technical (like the complete reference on firewalls) then I'll take a minute in the morning to PR chapter one. During the day I'll skim it and activate here and there for a minute or two. The next day I'll work on chapter two. Of course, this assumes you don't have to know the subject right away. But doing it in blocks like this is definitely viable.
~NeverSpeak