I’m a proponent of open-plan offices.  Browsing around this morning, I stumbled across this interview with Rob Pike from 2004 which touches on a lot of things, but one thing in particular struck me: his description of the “Unix room”:

One odd detail that I think was vital to how the group functioned was a result of the first Unix being run on a clunky minicomputer with terminals in the machine room. People working on the system congregated in the room – to use the computer, you pretty much had to be there. (This idea didn’t seem odd back then; it was a natural evolution of the old hour-at-a-time way of booking machines like the IBM 7090.) The folks liked working that way, so when the machine was moved to a different room from the terminals, even when it was possible to connect from your private office, there was still a `Unix room’ with a bunch of terminals where people would congregate, code, design, and just hang out. (The coffee machine was there too.) The Unix room still exists, and it may be the greatest cultural reason for the success of Unix as a technology. More groups could profit from its lesson, but it’s really hard to add a Unix-room-like space to an existing organization. You need the culture to encourage people not to hide in their offices, you need a way of using systems that makes a public machine a viable place to work – typically by storing the data somewhere other than the ‘desktop’ – and you need people like Ken and Dennis (and Brian Kernighan and Doug McIlroy and Mike Lesk and Stu Feldman and Greg Chesson and …) hanging out in the room, but if you can make it work, it’s magical.

Serendipity is an underrated element of the magic of creation.  As is collaboration.