Here is a compact elliptical machine that fits under your desk to give you a workout while sitting. The Vibrolegs Elliptical has a built-in display to show your stats. It has 3 programs and 5 resistance levels for you to choose from.
This elliptical machine weighs only 13lbs, so you can take it around easily. It has anti-slip bidirectional pedals and also a convenient smartphone holder.