I have a Lenovo X61t. It's their small laptop that is also a tablet. I run Ubuntu Linux on it but this Instructable is probably Windows compatible.

I bought a VESA mount arm from Ergotron. I wanted to be able to reposition my laptop for better ergonomics but I wanted to be able to still use it as a tablet (possibly while standing). There are several VESA mount options for laptops, but none seemed to suit my needs. I decided to build this out of Plexiglas and several screws with nuts and washers. Here's what you'll need to build this

Tools, etc:

An X-series tablet (The measurements may vary, I have the X61t).
A drill with appropriate bit.
Some measuring utensils.
A pencil.
Eye protection.

And some consumables:

1 sheet of Plexi that is 12" x 10 3/4" x 1/4"
2 sheets of Plexi that are 2" x 10 3/4"
4 5/32 1" metal screws
7 5/32 2" metal screws
22 5/32 washers
11 5/32 nuts

The Plexi and fasteners cost me about $20. I even had the Plexi cut (if you live in/near NYC go to Canal Plastics like I did. It's a great resource).

Step 1: Measure/drill Holes in the Large Piece of Plexi

Using your measuring device put markings for four holes in the bottom edge of the large piece of Plexi. I centered them and spaced them 2" apart.

You will need to put three holes at the top as well. On my laptop there is a GSM modem antenna which makes the top uneven. I chose to put the three top screws off to the side so that it would not interfere or put any load on the antenna. YMMV depending on your laptop.

I also used the laptop itself to determine the placement of the holes. This was easy and helped me to make sure that the laptop would fit in the final product.

Step 2: Measure/drill Holes in the Two Small Pieces of Plexi

Using similar techniques I plotted the position of the holes for the two smaller pieces of Plexi. These will need to line up with the holes in the large piece and make their way around the laptop.

Step 3: Mark and Drill the VESA Mount Holes in the Large Piece of Plexi

With the help of some measurement instruments and just eyeballing it, you can put four holes in the large piece of Plexi. Center it in both ways. This is what will make the laptop be held by the VESA arm.

Step 4: Mount the Large Piece of Plexi to the VESA Arm

Do this by using your four 1" screws with washers at both ends and a nut for each one. Make sure this is snug. The plexi only cost $20 but if that laptop falls you will probably not be very happy.

Step 5: Attach the Small Pieces of Plastic, Insert Laptop, Enjoy Better Posture

Attach the smaller pieces of plastic to the larger one using the rest of your screws. Do not tighten them very much. Slide the laptop in and tighten things up for a snug fit.

Read the manual for the VESA arm you have. You may need to adjust the arms tension depending on the weight and position of your laptop. You should also position your laptop so that you are comfortable and in a neutral position. It's good for you.