If you're stepping out to grab a coffee, decency requires you ask your co-workers if anyone else wants one. But on the way back to the office, you curse your own decency as you juggle multiple hot cups and the phone rings or you need to pull out your keys.
A nifty solution is this carry-bag for coffees, apparently from a chain. As the page showing the bag and the comments on it are in German, we were unable to get more info about it, but Google Translator did let us read some excellent comments like these:
So I find it great. This hole every day I think decaffeinated coffee with 0.1% milk. The will for me gepustet extra cold, so I opened my mouth or by not verbrenne get stomach pain. You are all so common :-(