Epson's Electronic Ink + RFID = 21st Century Price TagsA new technology from Epson combines electronic paper (Update: developed by E Ink Corp.) with RFID tags to display the prices of products at stores. According to Nikkei Electronics, Epson has presented the technology at the "Embedded Technology 2004" convention, going on since the 17th.

Clearly intended for storefronts, the small displays can show 8 bytes of character data. Through a combination of RFID and some new fancy electronic paper technology, Epson supposes the displays would be used to easily change the prices of products; "this would drastically reduce the personnel expenses required for changing prices at a store," says a representative.
So what the hell does Epson have to do with electronic paper? Glad you asked — the company's inkjet printing technology enabled them to join the wireless tag IC with a flexible substrate. While conventional methods (wire bonding) would allegedly require some 50 nanometers, inkjet printing technology requires a mere 5 nanometers. That would be a helluva paper cut.

ET2004: Epson, new display combines wireless tag and electronic paper [Nikkei Electronics]