We've sung the praises of standing desks many times before, but if you aren't quite ready to replace your desk completely, you can try it out with this simple trick.
Most standing desks require you to replace your old desk entirely, or at least DIY something together. If you want a quick, easy, adjustable free standing desk just to see what it's like for a week or so, blogger Greg Schlom explains, in illustrated form, that you can just put your chair up on your desk:
Step 1: Lower your chair to the minimum. (If you don't have an adjustable height office chair, you can stop here and get yourself a decent chair)
Step 2: Get your fat arse off your chair, put the chair on the desk, and your Mac Air Book Pro on the chair. (Of course, if you have a SPARC server, you have two problems now.)
Step 3: Adjust the height of the chair as needed, and enjoy your new standing desk.
It isn't exactly the most polished hack of all time, but it is the quickest and freest way to try out a "standing desk" for a week to see if you like it. Hit the link to read more.