After about a year on the road Angie and I decided we really wanted an insulated growler. The original thought was so we could drink cold beer. We wanted something all metal (excepting gasket), and Kleen Kanteen seemed like just about the only option on the market. Finally we bit the bullet and picked this up:
We've had a 1 pint Kleen Kanteen thermos each for some time, and we love them. We use them instead of mugs for drinking tea, and often use them hiking to carry warm drinks. I've found mine to be pretty great for water while skiing as well. We use these every morning (and many other times as well), making them among our most used utensils.
After we got the Growler we suddenly realized we could use it for storing MILK! It will keep something cold for ~48 hours. This means milk will still be tasty for ~72 hours, which is AWESOME. Yes we have tested this, and it works even in warm weather. We both adore milk. If we can find milk in a glass jug it's even better, we can walk out, pour the milk in to the growler, and then return the glass to be refilled. No waste, we get the deposit back, and we get good milk.
Next we realized we could use it for tea. In cold weather it's great to just drink tea all day, but boiling water over and over again gets annoying. Using the big thermos and our small thermoses together we can make 3 liters of tea at a go. Conveniently this is as much water as our largest pot (Angie's cast iron pot) fits anyway. As a bonus the flip-top (in contrast to a screw top) makes it easy to leave tea-bag strings hanging out while the tea is brewing. The silicone gasket still seals plenty well.
Of *course* we've also used it for beer as well :). It keeps the beer good to drink for long enough to drink it the next evening around camp and still enjoy it. Also, it feels good to walk in to a brewery and walk out with beer, and again... no waste.
Overall we feel really silly for not having bought one a year ago. Using it for beer turned out to be a bonus, with milk and tea being by far our favorite and most common uses.
For anyone on the road who loves milk or tea I HIGHLY recommend picking one of these up. In fact, I will probably keep using it instead of a tea-pot for drinking tea when we settle down someday.