We previously peeked at a transformation of IKEA's productive and popular Jerker desk into a treadmill-based desk, and now another more elegant and spare adaptation has surfaced. Using the (sadly discontinued) desk's adjustable height, it's a lot easier than you might think.
John Carter in Indiana wrote into Ikea Hacker with all the details on how he assembled his Jerker desk over the terminal of a standard treadmill. He had to make his own cross braces and add a little wire shelving to hold his computer, but it's a surprisingly spare setup when finished. Carter also notes that, while the desk is no longer made by IKEA, they are often found floating around the internet, often for very cheap, and you only need two of the four original legs to create his treadputer.
Jerker treadmill desk [Ikea Hacker]