I think Brian, you will find the cost of installing such a think will far outweigh the additional electricity you produce. I know you can buy mountings that can be relatively easily changed for the winter and summer months, but in terms of tracking the sun across the sky, I am not sure for residential systems they exist.
There are devices called solar pv trackers that orient the pv panels to the direction from where the maximum sun rays come from. There are two axis trackers that can meet your purpose. Check this link -http://www.pvresources.com/PVSystems/Trackers.aspx. Given the season when there is less sunlight, it is less likely that you get a good pv production. Additionally you can also try using energy diverting switches. I have posted about one in this thread – http://www.thegreenage.co.uk/energy-saving-forums/topic/turn-down-thermostat-on-hot-water-tank/#post-14565.
I have installed a 3.2kW solar system on my home, however unlike most the system is at ground level on mounting. i have noticed (like most I guess) that the amount of electricity I produce in the winter is very small. Is there an automated system that tracks teh path of the sun that I can install to increase my return? I guess it would bneed to move in two dimensions, so not only can it be steeper to benefit from the sun lower in the sky but also rotate with the suns movement across the sky. Any thoughts or ideas for such a system would be greatly appreciated (or even better a company that builds this sort of mounting!)