​Calf Raises
Muscle contraction helps the heart pump blood.  Especially in the lower extremities where gravity is exerting its effect, making it more difficult to push the blood up to the heart.  This will help the heart and your leg muscles!
Bilateral Shoulder Shrugs, (BS's)
Tight shoulders and necks seriously hamper blood flow, can cause headaches and these will stifle creativity...to stay competitive, take stock in your physical health.  
If you continuously suffer from pain in the neck please consult a Chiropractor.  
Shoulder Flutter
Again, this will help the tight, achy muscles of the neck, shoulders, and mid thoracic spine.  Excellent to increase blood flow, stimulate mechanoreceptors and wake up the brain!
Soldier Marching
This will encourage lower extremity stimulation and blood flow.  It will help to keep a healthy lower back.  
​Jumping Jacks
This one can be a bit disruptive in an open floor plan, so go find a closet and get your body movin'!
Religion Squats
Great to break the stagnation of sitting a non-movement in a day at the office.  
​Might need to find a closet for this one, as well :-)
Push-ups and Reverse Push-ups
The end of the desk must be sturdy and insure that you do not throw the desk off balance.