I was wondering what kind/gauge of wire can/should I use to run some of these through my house/room. I am a newbie and am clueless...could i use phone cable? Or speaker wire? Or ?? I would prefer it to have more than one wire per cable, just for ease, but i don't know.
... has better prices, if you include p&p... and you'll get personal service, and support someone who's interested in the customer.
And if you want lower prices still... but with some risk... the sensors are often on eBay
But! Wire?
I'd use Cat-5.
But you need to understand something....
If you are putting several sensors on a single leg, they need to be like rungs across a ladder. You can't use a "star" topology... unless you either have a "hub", or have a digital pin dedicated to each sensor.
Having said all of that, the DS18B20 is an EXCELLENT choice... but you can't just hook them up like light bulbs....