"Sitting is the new smoking," is the melodramatic phrase you've probably heard from a chiropractor or yoga fanatic. While that's probably not an apples-to-apples comparison, sitting for long periods of time has been shown to be quite hazardous for your back. If you work at a desk (or on the couch) for long periods, a standing desk or desk converter that forces you to your feet for a while can really help. This sturdy Flexispot standing desk converter is on sale right now, down 50% to $60 on Amazon. It normally sells for twice that, as do most other comparable models we found. 

This two-tier desk converter is fully adjustable so you can go from sitting to standing with ease. It's also lightweight but large enough to fit two full monitors.