I have one addition to that you might like if you have an iPad 2 or other tablet with a camera.
Also works for warranties.
- Create a Note Link to your note with the manual for your thermostat
- Paste that Note Link into a QR code generator (like this one) and get a graphical QR code you can stick to your thermostat
- When you need to change your thermostat battery, point your iPad at the sticker and RTFM (Read the Fine Manual).
There are a bunch of ways to use QR codes to enable going paperless with Evernote. You need a device with a camera, a website to generate QR codes, and a printer. Ideally, a label printer, since you'll be sticking the codes on things.
QR codes are also useful for ordinary notes. You can even include the QR code to the note in the note itself. Why would you want to do this? Well, suppose you have something you want to stick on the fridge (I'm going to China tomorrow, and my itinerary is going up there). A QR code to the note itself means my itinerary is there, but if there are any updates (including those I make while I'm in China) the note will contain them, and my family can easily check just by pointing a phone at the note. This is very useful for anything volatile for which you still need a paper copy.
One reason I would really like "evernote://" style URLs to notebooks or searches is because I could think of a lot of things to do with them using QR codes.