On this site you can find a nice and fully documented project using 16 1 wire temp sensors with a bunch of Atmegas:
Introduction:
http://66.249.93.104/translate_c?&langpair=de|en&u=http://s-huehn.de/elektronik/tempmess/tempmess.htm
How to connect several 1 wire buses to an Atmega8:
http://66.249.93.104/translate_c?&langpair=de|en&u=http://s-huehn.de/elektronik/tempmess/tempmess-sm.htm
Edit: Google translator is acting up, maybe these links will work?
http://translate.google.com/translate?u=http%3A%2F%2Fs-huehn.de%2Fe+lektronik%2Ftempmess%2Ftempmess.htm+&langpair=de|en&
http://translate.google.com/translate?u=http%3A%2F%2Fs-huehn.de%2Fe+lektronik%2Ftempmess%2Ftempmess.htm+&langpair=de|en&