Sometimes you need a little screen to tell you something you are interested in, that is occurring on your network.

With a tiny Arduino clone, a HopeRF transceiver, a small OLED screen, and a small LiPo battery, you can have an inexpensive position-aware output device that you can just put anywhere you need.  It is totally standalone, and is "dumb" in that it is only focused on displaying what it is told to display.  The Reactron network can address it wirelessly and push data to it.  It uses statistically weighted triangulated RSSI to determine where it is in the room, since there are many other RF transceivers in the room.  This has been good enough for my purposes.

OLED screen side.  JST connector is for recharging the LiPO.

Reactron microcontroller side, HopeRF radio sandwiched in between. 

I had taken to wearing one on my wrist to determine what was happening at places not near me, the idea being that I was near the things I was near, so I just needed information about things I was not near.  The Processor behind this was one of the first implementations of a simple Recognizer, where the RSSI was effectively a Collector input.  Later I wanted to leave a few of these lying near a thing I was interested in, so I need the opposite Processor - push data to the display that was concerned with the nearby thing going on.  Then, I needed to tell these two usages apart, and could only do so statistically, so the Recognizer was born.  

After that I realized I needed both things on one display.  That is, data concerning the nearby thing, and anything anomalous or important happening with remote things, as a secondary display.  That helped me to not be distracted with "checking", and then that became solidified as the main idea behind the ambient Integron as a passive (but active if you need it) interface device.

One thing on my list that I have not gotten to yet, is to make a nice case for these.  Maybe out of NinjaFlex.  They are small, and they are portable, but the OLED screens are delicate and they do crack when they fall to the floor.