Thermostat recommendations?

[Bradley Plett <plettb@xxxxxxxxxxx>]

I am completely new to the world of home automation.  However, my
thermostat needs to be replaced, and I would very much like to replace
it with something that I can program from my PC.  Having said that, I
don't really know where to begin.  Has anyone got any suggestions for
me?

Here is a further elaboration of my situation.  I would like,
eventually, to put controllable dampers or flow controls or whatever
they're called into the pipes from my furnace/AC so that I can control
different zones separately.  However, I can't afford that right now.
So, I want to start by replacing my thermostat, with a view to
building the system out further if/when I can afford more.

I have done a little reading on the net but it hasn't gotten me a lot
closer to a solution just yet.  I've read a little about X10 and
RS-485, but being new to this field, I generally get confused before I
get very far.  Can someone offer me guidance as to exactly which
components I'll need to buy now in order to hook up a thermostat to my
PC and be able to control it?

Thanks a lot!
Brad.