Numerous people have been combining 2 of IKEA’s LACK side tables to arrive at a stand up desk retrofit for one’s regular office desk. I looked at some of the other options in the LACK table line, and found there was a coffee table L 35 3/8″ x W 21 5/8″ x H 17 3/4″ that includes a lower shelf: http://www.ikea.com/us/en/catalog/products/00095036/#/10104295
This seemed like a good match for my corner-style cubicle desk, and I liked the fact I could modify and repurpose the lower shelf to become my keyboard and mouse tray. I used all of the parts that came with the coffee table together with some 3/4″ x 1 1/2″ poplar to provide 2 cantilever braces and 2 cross braces (not visible, hidden beneath shelf). I needed a few 1 5/8″ and 1 1/4″ construction screws, and I also trimmed the width of the lower shelf on the table saw so that it would fit between the legs as shown in the picture. The LACK coffee table is currently $19.99 plus shipping from IKEA, and the poplar or an alternative cross brace stock can also be pretty inexpensive at your local home improvement store. The result is an affordable and well-appointed standing desk solution.
Here are links to other blogs where people have done IKEA retrofits: