I know this is a topic that lots of people have posted about this, (see this google search for some other posts)
If you are do busy, where is the space to allow your mind to run, and think of new ideas, reflect on past experiences, reinterpret information and generally become inspired.
Often the time that we call procrastination, apart from giving the brain a rest from the task at hand, is used for gaining knowledge, engaging others, or being creative.
The key to procrastination is to utilise the value of procrastination i.e. act on the idea, allow the creativity to impact the work you do, and solidify relationships.
Ultimately the time spent procrastinating may be worth more that the task you were completing at the time.