One of the questions at the muug meeting today was about temperature and humidity readings/monitoring.
The 1-wire devices are quite easy to use .. there are a few links I've saved from prior here: http://delicious.com/ve4drk/1-wire -- they're about a year or so old ...
an interesting take is using the owfs (http://owfs.org/) with openWRT ( http://openwrt.org/ ):-) yes -- you know it can be done :-)
I know another local who has used these .. he has a nice display and info on how to do it .. it is: http://www2.ertyu.org/temp/conditions.php
Dan.