They have a theorethical 0.0625 (yes, .0625!) maximum accuracy (albeit, a conversion takes 0.75 sec). I got all of mine from MAXIM. They are pretty generous with the samples. I'm thinking of using them for some homemade hydroponics.
edit: hmm, that's not exactly what I'm looking for. It says nothing about multiple slaves on the bus, the required rom enumeration. i know the theory, but it's practice that kills. maybe i'll write a tute when i'll understand this.