I really wanted a geek desk, but they're like 1,000 dollars. So I built my own for about 200 bucks (not including top). This is simply a regular desk that can rise up with a push of a button and turn into a standing desk. It takes about one minute to raise, speedier linear actuators are expensive.

Parts
Pair of linear actuators (found on eBay for 150)
Premium pine (Home Depot 50 bucks)
12v power supply (found in my electronics junk box)
wire
screws
electrical tape

Tools
miter saw
drill
clamps
wire cutters
stapler

Step 1: Design

I wanted to figure out how this thing would all fit together before I started making any cuts. So I drafted a 3D mock up in Autodesk Maya. I know Maya is usually used for animation, but it’s what I know, and it works. I wanted to take my current IKEA desk and just swap out the static legs for dynamic columns.

Step 2: Gather All the Parts

I found a pair of linear actuators on eBay for only 150 bucks shipped. They came with a wiring harness too which is great because I don’t know anything about electricity. They have a 16 inch stroke and are rated at 220 pounds each, but I wouldn’t put more than two monitors on this desk.

I went to Home Depot to find some wood, I ended up spending about 50 dollars for premium pine. All the cheap pine was warped and I figured a telescoping column should probably have straight edges.

Step 3: Cut and Assemble the Legs

I’m basically going off my 3D mock up here for measurements
I mounted the linear actuator to a small wood base, then built the inner column around it. Then the outer column around the inner.
I tested the first leg built to see if it could lift the table top. It did, so I built another one.

Step 4: Attach Legs to Table Top

This was pretty simple. Just keep in mind that if you plan on using an IKEA table top, most of them are just made of cardboard, so drilling legs into it isn’t strongest hold.

Step 5: Mount the Switch and Route the Wires

I just drilled out a large hole in the side of the table top to mount the switch
I ran some extra wire so the desk could rise without snags.

Step 6: Finished

Takes about 60 seconds to change position, cost about 200 bucks.

Recap:
If I spent maybe another 200 on the linear actuators I think they would be a bit faster and stronger. Also I would have rather had 18 or 20 inch stroke, but 16 was the most affordable.
The legs are definitely version 1.0, I know they don’t have to be this big, it was just really easy to make it this way.
I will eventually add something to program height positions. So I could just press the button once instead of having to hold it down. I have a Raspberry Pi laying around here somewhere.