Great job from Vimeo member Oliver for this DIY motorized Pico Flex Table Dolly. It's a direct friction based drive wheel, which doesn't require much torque. The dolly rolls very easily with little effort from a motor. I was testing out something similar several weeks ago using a pulley wheel to a continuous rotating servo found (here). I used the same basic battery box, continuos rotating servo, and speed controllers as in the DIY motorized JuicedLink slider project. You can find a list of those parts (here). I can see that Oliver is using a servo tester, which is a much cheaper solution than the servo controller I was using. [Thanks Oliver]
If i'm correct, that servo tester is just the basic ones found over at eBay (click here).