When my children were little, I used to feel guilty taking time to read a book, so I would take the book with me everywhere I went and when I had a moment (like sitting in the carpool lane) I would read. The problem is, we spend a lot of time feeling guilty, especially when we are doing nothing. We feel we have to keep our kids busy, keep ourselves busy, and justify the times we aren't working like mad scientists late into the night doing something!
However......., research shows that we are at our most creative when we are "doing nothing." So be idle, sit and stare at the clouds, or the water, or out the window of you office, and find your mind doing a lot, creating the next great thing or solving problems.