I stumbled across a very interesting video about a clever idea from Timo Arnall and Jack Schulze - people worth watching if you are interested in novel and thoughtful design. I was following a link recommended to me by Sam Kinsley about the Making Future Magic project from Berg London, using ipads to create light animations. That work is well worth a look too.
But this video that I want to point people at, Immaterials: the ghost in the field, is all about "exploring the spatial qualities of RFID, visualised through an RFID probe, long exposure photography and animation" Basically that means they used a little LED light attached to an rfid tag and held it near an rfid reader to see when the tag and reader talked to each other, thus mapping out the edges of the range of the rfid. The video has a very clear explanation of why this is important for designers using rfid, and is intriguing enough to watch even if you aren't using rfid in your own work.
They are visualising the shape of the readable volume of different rfid tag readers - you can't see this footprint of rfid any other way, which can be a problem if you are a designer who needs to know where and at what angle to embed tags in relation to readers. Making a visual representation makes it easier for the designers to know where to place the components. And even if you aren't that bothered by any of that it's still worth watching.