A stand-up/standing desk is a fun experience which might bring the change you need in your office. There are a few ways of achieving this, out of which the cheapest is to build your own, out of boxes and stuff you have around the house.
If you are not into DIY stuff, you can always go for the middle way, the Monkey desk which you can order online.
Also, if you are serious about this, you can go for more elaborate solutions, like buying a more expensive desk or ordering your own.
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