I had a bike crash at the start of the year (2011) which resulted in me being out of action for several months. While laid up on the sofa feeling sorry for myself I caught a couple of articles detailing the switch from a seated desk to standing. I figured I would give it a go and spent ~£100 on an Ikea Fredrik, you can also convert it to sitting with some help.
For the first few weeks my feet hurt and I could only get through from 8-3 standing (with a 20 minute break for lunch). At this point I am fine standing for most of the day and I also think it has helped with my posture – spending fewer hours slumped at a keyboard is a good thing, right?
Here a couple of photos