Nest is perfecting the thermostat. And it's been such a big hit, investors have decided to pour a boatload of money into the company. According to GigaOm's Katie Fehrenbacher, Venrock, Google Ventures and others have given Nest $80 million at an $800 million post-money valuation. Fehrenbacher says Nest is shipping between 40,000 and 50,000 thermostats per month. A good number of those items are be