1. The subconscious mind keeps working.

Unlike physical labor, which stops when the worker stops, the mind keeps working on mental tasks when you're not thinking about them. This powerful process of problem solving happens when you're surfing the Web for fun, watching TV and especially while you're sleeping (hence the phrase, "Why don't you sleep on it?").

Internet slacking helps this process by getting the conscious mind, which is prone to getting stuck or blocked, out of the way.

2. It gets personal things off your mind.

If you're worried about your kids, or missing your spouse, or preoccupied with some pressing personal matter, you're not going to hit all mental cylinders in your work. Social networking, Twitter and personal e-mail let you quickly get in touch with friends and family, find out what's going on, then get back to work with full attention.