It doesn't really take any longer to stand up while picking up your coffee cup than it does to stand up anyway... and I leave my cardigan-type-thing (though not my actual coat) on the back of my chair, so again it's easily to hand if I have to leave the office in a hurry.

If everybody stops for a couple of seconds to pick up coffee and coat, then a) they're obviously not running around in a panic, which is good, and b) it probably means that there isn't such a huge bottleneck as there would be if everybody charged straight for the doors.

At least, that's my theory, and I'm sticking to it. :)