I have spinal problems that prohibit working from normal chairs, but standing at a desk/counter for more than a few minutes causes me major fatigue and knee/hip problems. My solutions are many, including multiple work surface heights (some adjustable), constant repositioning and no static poses, frequent movement and stretching breaks, weed, and this:
http://www.focaluprightfurniture.com/ My favorite seats are the Mobis and Pivot, which I use with an electric-lift workstation I built myself.
Strictly standing alone at a desk really sucks long term, but a variable sit/stand perching position is much easier on joints and way more productive in general. Adjustability and variability of hip angle is crucial, and an angled footrest is imperative to make such systems work properly (activates hip flexor/extensor muscles and avoids incorrect lordosis from perching).
http://www.aeris.de/ has another great product line, but their sit/stand seat is about twice the price compared to Focal. Also Focal is run by reknown shoe designer Martin Keen. If you're near PDX or SFO,
http://ergodepot.com has a couple neat retail showrooms (with very nice salespeople) where you can bring your work and hang out for a while, to try out all the products before you decide.
Btw that pic of the guy with floor tile missing is hilarious, akin to some of the kludgy solutions I've tried over the years.