A few thoughts regarding that old cliche "work smarter, not harder":

• If you are going to work smarter then make sure you measure the right thing: The on-line shoe business Zappos rewards call center employees for the relationships they build with their customers, not for the number of calls they take.
• Are you breaking before you break? Accountants at Ernst and Young who went to the gym in the afternoon and took brief breaks every 90 minutes improved their overall productivity; while accountants that took their vacation time showed higher improvements on their performance reviews. 
• Taking a catnap sometime between 1 p.m. - 3 p.m. is a proven way to boost productivity and work smarter. 
• If you are improving a skill or learning a new skill research shows that the highest performers practice more often (duh), practice more in the mornings, and practice super-intensely followed by a break.
• Research shows that you are more likely to work smarter towards a specific goal if you partner up with someone (or better still have 3 - 4 accountability partners) and make it fun! 
• And speaking of working smarter, I had to toss this in as an aside: Studies show that people rate coworkers with a great sense of humor as being smarter than their more sour-puss colleagues!