If you’re not using Fluid yet then you need to check it out. It’s a very cool app that I think everyone will like. I use it a lot. Give it a try. Fluid – Free Site Specific Browser for Mac OS X Leopard.
Here is a great article on why using a Ballance Ball as a chair is a good thing for your back, balance, bloodflow, etc. 10 Reasons to Use an Exercise Ball as Your Chair | GearFire – Tips for Students.