Step 1: Parts List
Tubular motors from RollerTrol.com are affordable (at least in the world of tubular motors for shades), relatively quiet and easy to work with. The motors require 2A 12V DC power and can be reversed just by changing polarity. They even have an included rotation counter so that the up and down limit on your shade is managed by the motor itself.
Rollertrol.com DC Motors
My home is controlled with INSTEON so, naturally, I have come to an INSTEON automation solution. INSTEON recently released a new module, the Micro Open/Close controller which is essentially a dual-relay module. One relay responds to an UP command, the other to the DOWN command. The only cumbersome thing is that the relays operate at 120V AC, not the 12V DC we need for the motors. INSTEON does offer a dry-contact relay module, the I/O Linc, but you would need two I/O Lincs to control a single shade (one to control up, the other to control down).
INSTEON Micro Module
Any 12V DC, 2A power supply will do. My solution will require two supplies for each shade. More advanced hobbyists can probably wire up a polarity reversing switch that only needs one supply. I happen to have a bunch of 12V adapters around, so we're going to just use what is on hand.
12V DC 2A Power Supply
Because we will be wiring both supplies to the motor at the same time, we need a way to break the circuit. Any 12V SPDT relay should be more than adequate. I used automotive relays as they were easy to wire but certainly overkill.
12V SPST Relay
Step 2: Installation
Mounting the motor is rather straightforward. The RollerTrol motors ship with mounting brackets that screw to your window frame and mount via a small metal flange. As for tubing, if your window distances are shorter (4' or less), SCH40 PVC pipe works rather well. I would probably take a motor mount to your home center and test the fit though. I found enough inconsistency that I had to try several different pipes each time. If your distances are longer, RollerTrol suggests metal electrical conduit. Make sure your mounting is level or your shades won't hang properly.
Route the two motor wires through the mourning bracket and out of the way of any rotations. The last thing you want is for your shade to somehow catch the wires and rip them out of the motor. If you are placing multiple motors near each other in a bank of windows, you might consider using ethernet to gang together different motors. With one ethernet cable, you can pass power to four motors. Ethernet is cheap, easy to run and should be more than adequate for powering your motors. Keep length in mind though and always test before you commit anything to drywall.
Step 3: Installation - Wiring
In a nutshell, connect one 12V supply to each of the two relay terminals on the micro module. Wire the relays so that they will be powered by the 12V supply and the normally open contact will close to send power to the motor. It may seem wacky, but without the relays in the mix, power doesn't flow properly to the motor.
Step 4: Almost Finished
Controlling the shades is the best part. You can keep it simple and pair your Micro Module to any other INSTEON controller or you can go off the deep end and build a custom interface for just your solution. My home is powered by Perceptive Automation's Indigo using their webpage-based control pages to build a custom user interface for my shade setup.