I've been wondering lately whether there is such a thing as a thermos you can sip from which is also leak-proof when travelling? I've got two which disappoint in different ways, and wish I could combine their assets...

It's not leak-proof, but I have to put a word in for the Klean Kanteen stainless-steel thermos. I brew my tea around 8:30 in the morning and my thermos keeps it hot until 1pm or so, and warm almost until the end of the day. (I work in a lab where I'm not allowed to have food or drink, so I usually end up sipping at my tea in the breakroom throughout the day.) It's plain-looking compared to some of these cute vintage deals, but it gets the job done. :)

moomins! yaaaayyy!

@marmite - yes(!)... I picked this up at my local coffeeshop, but Thermos/Nissan makes a fantastic backpack thermos with a flip-top lid and a built in silicone gasket. I fill it up in the morning, throw it in my purse and the coffee I can't drink is still warm by the time I get home from work. Best purchase ever & it's pretty banged up - no leaks yet. Lifetime warranty, too.

[and no, I don't work for Thermos(TM) - I just can't believe I own something that actually works properly]

Does anyone know of any extra thin thermoses? None of the pockets on my bag are big enough for the normal sizes, and it's getting kind of annoying when I have to carry around the thermos all day.

How about thermoses for food? I don't have a microwave at work and I would love to eat hot food (even warm food) for lunch. Any recommendations?

For hot liquids, this is my long-standing favorite:

http://www.amazon.com/Thermos-12-Ounce-Stainless-Steel-Tumbler-Infuser/dp/B00004S1CV/ref=sr_1_7?s=home-garden&ie=UTF8&qid=1288793119&sr=1-7

Won't spill ever! The only downside is that it holds a rather small volume, but that's OK for bring tea or coffee into the office in the morning.

Totally second the recommendation from keltrue for the Thermos/Nissan one. I bought one 3+ years ago and it's still going strong. If I have a meeting that lasts all morning, the coffee is still warm at noon when I get back to it. And I can put it flat in my purse with no leaks. It's amazing!

@marmite I recently purchase a Klean Kanteen insulated "water bottle" and a cafe cap. It is BRILLIANT! The cover that comes with it is leak proof and when I am ready to sip (when I get to the train station) I switch to the sippy "cafe cap"

I have an unatural fetish when it comes to thermoses. But my absolute favourite Thermos is the wide mouth Stainless Steel Food Jar at 0.5L I can put soup, coffee, tea, spaghetti... you get the picture. It keeps things piping hot for an entire decade and its leak proof. The downside is its not gonna fit in an evening bag, it doesn't fit in European cup holders, and its not human so I can't take it into a dark room and have my way with it. But its definitely one of my best purchases- ever. In fact, I bought my first one in Canada, lost it, and felt the empty void so keenly that I spent an entire afternoon looking for a website to ship a replacement to the UK. Its now widely available in the UK, so I can stop worrying if I lose it again.