I’ve been using an adjustable height standing desk (AKA stand-up desk) since October 2012, and I love it. I feel more energetic, and it helps me maintain better posture. I've been sitting only 0-5 working hours per week, and standing the remaining time.
I started hearing about standing desks a couple years ago. I remember reading blog posts by local web developers, such as On Stand-Up Desks by Daniel Morrison of Collective Idea and The $40 Standup Desk by Brandon Keepers (currently working for GitHub).
After a lot of searching, I found someone in Holland (Michigan) who buys height-adjustable bases with hand-cranks from Germany, attaches flat desktops to them, and sells them on Craigslist for $100. I didn’t want a flat desktop, though; I preferred the desktop from the desk I already had, which I bought at a garage sale years ago. It's just the right size and has a nice riser (raised shelf). So, I bought the base for $90 and replaced the base on my desk. My final desk takes less than a minute to raise or lower.
Several people have asked where they can buy the same desk base. Unfortunately, the person I bought it from no longer sells them, and he won't tell me where he bought them. I can't see any text or identifying marks on the base; it’s quite generic.
Do you have a standing desk? Tell me about it in the comments.