The company I work for, Ergotron, has an excellent summary on their blog, regarding the concerns of sitting too much and some recent research on this topic.
http://blogs.ergotron.com/blog/2011/11/03/theres-a-reason-they-call-it-sitting-disease/
Unfortunately, many of us are stuck long hours sitting at a computer. Did you know just standing more each day burns extra calories, tones muscles, increases blood flow and ramps up metabolism and increases productivity. Encourage your family and friends to stand-up more.
Here's another new product from Ergotron (not yet released) that will help people stand and sit throughout their day.... and get the creative juices flowing.