Motorized Register
Wow, this is a great (and cheap way) to control the dampers in your home…

Compare: in existing zoning systems, the cost per room is anywhere between $600 and $1300, in this case, it is approximately $10 for a servo, and approximately $3 for a sensor, which makes it less than $20, if you count the price for all those small things in there.

Impressive, isn’t it?

Initially, there were concerns about the longevity of this device – all in all, neither of the original components (the stock registers and the stock R/C servos) were intended to be used in “always on” mode…

DIY Zoning: Dampers – [via] Link.