[1] http://www.amazon.com/FitDesk-v2-0-Desk-Exercise-Massage/dp/...
[2] http://www.amazon.com/dp/B00B1VDNQA/ref=psdc_3407781_t3_B00C...
EDIT: Forgot to mention, when I say exercising, I mean during the same time where you would be sitting (e.g. during work, continuously)