While it does seem useful, I’d be curious of the security implications; does wearing such a thing on your wrist make it easy for others to scan your credentials? I’m not incredibly familiar with NFC chips, but they do seem to have a much shorter range than most regular RFID chips, which seems like it might help. However all anyone would have to do is embed a reader under/in the table you sit at (say, at work or at your local coffee shop). Maybe we can keep the circuit hidden in a faraday cage, such as another (modded) microSD card slot, and just pop out the chip when needed.