The very first question I get was: what kind of hardware are you using ?
In fact, I searched a little bit on the web, and I came to the conclusion that the simplest solution was to use Maxim 1-wire bus. This bus is very simple (2 or 3 lines are needed, despite the name), and the devices I need (temperature probes) are simple and cheap !
There is a very interesting introduction video on Maxim’s web.