I've been using the Snow Peak 700 for about 3 years as my tea kettle in my apartment. Though that hasn't been exactly the original use case of the mug, it has proven to be a reliable vessel for food and drink.
This repost still holds true with my original review. You can read it here.
One of my favorite and most used pieces of equipment, the Snow Peak Trek 700 mL will have a permanent place in my kit. Not only is it useful to drink from it is also ideal for cooking small meals as well.
In addition to having a permanent home in my kit the Trek 700 also has found a place in my kitchen as well. I'm constantly using it to boil water and drink liquid from. I've also used it when i've needed another pan to cook with in a pinch. (Talk about versatile!)
The Trek 700 features some fold out handles and a cover (useful for keeping the heat in whiling boiling). Be careful though, the handles will be hot after being placed on a stove for a while.
Another drawback is the fact that you need to wait until it cools enough to drink from it. In my opinion, it's a small price to pay for an overall net utility gain. Overall, the Trek 700 is a great piece of equipment and weighing in at only 4.8 oz you'll barely know it's there!
Overall, I give it 4 out of 5 stars because there is no way to dissipate the heat after cooking except for waiting for the cup to cool down. That means no drinking directly from it until it is safe to put your lips against. There is an option to purchase Snow Peak's "Hot Lips" for $6.95 + shipping. I'll give them a whirl and report back.
Update 8/14/16: I bought a pack of the Hot Lips and they seem to be sufficient in preventing me from burning my lips after boiling a mug of water. They only wrap around on the front though so you still need to be careful with your top lip. When you buy the Hot Lips it comes in a pack of two. I'm assuming because they wear out over time. Will update again soon to see how they hold up over repeated use.