After attending CES2017 (Consumer Electronics Show) in Las Vegas this month, I concluded that the following device is inevitable, so I started thinking about what sorts of computations & patterns that might be obtained. One of the interesting things is the progress of "wearable computers", in which computation is embedded in socks, gloves, shirts, glasses, etc. I haven't seen a fully-electronic T-shirt yet, but it's inevitable. By "electronic T-shirt", I mean one with a (bit-mapped?) display on the front & back which can display any stupid thing that your heart desires -- e.g., "I'm with stupid", etc. If there is a display on your sleeve, you could literally wear year heart on your sleeve. Now such a stand-alone display is interesting, but would get boring after perhaps 5 minutes. Far more interesting is a display *that senses & reacts to other people's displays* -- probably by using Bluetooth LE, ANT+, or some other short-range wireless technology. You've probably heard the phrase "he was swayed by the last person he talked with"; an old joke recognizes this tendency and suggests that such information simply be displayed on his forehead. Well, an electronic T-shirt could do exactly that: indicate some amalgam of the electronic T-shirts that our target T-shirt had been recently close to. So, what if each such T-shirt had the same finite set of states, and all the T-shirts had the same rule for combining the states of the N closest T-shirts in order to compute this T-shirt's next state ? What kinds of computations & patterns could be obtained from such a cellular model? One could implement such a device today using Bluetooth smartwatches or smartrings (yes, they were at CES2017) communicating amongst themselves; of course, displaying the results on a T-shirt would be a lot more dramatic. BTW, this sort of model isn't 100% novel; I referred to a similar model here last November: SCHELLING, T. 1971. "Dynamic Models of Segregation". Journal of Mathematical Sociology 1: 143-186. https://www.stat.berkeley.edu/~aldous/157/Papers/Schelling_Seg_Models.pdf