Could this word to store a wallet key?

[SurReality89]

http://www.adafruit.com/products/789

[Longmarch]

This is kinda over my head, but maybe this youtube video might give you some ideas:

https://www.youtube.com/watch?v=GklBmrx2jJI

[P_Shep]

That's what Slush's device should use... NFC.

[Longmarch]

Like I mentioned before, I don't completely understand all the tech involved (more on the BTC side than the NFC) but I think there's a serious opportunity here for someone.

More physicality would really be a benefit for BTC.  The ability to literally toss BTC onto a countertop in exchange for goods and services would accelerate adoption.  NFC could be used (it seems) to load, read and unload chits in a convenient way.

All that's really necessary, in my partially informed view, is a low-cost reader.  Something like a plastic mat with an NFC coil in it. 

The chits might also be made to restrict themselves to specific amounts of bitcoins, and broadcast a simple on/off signal to verify that they are loaded. (Example: a 5 BTC chit has a '5' engraved on the outside.  You put the chit on the mat and the cashier immediately sees whether the chit is full or empty.)  This way the chits can be traded back and forth as physical currency until someone needs to unload them for whatever reason.  Conceivably, the NFC could also power a color-change in the chit for visual inspection. 

Or something like that.  My point is that there seems to be some potential in NFC for bitcoins, and I wouldn't mind knowing that someone is working on it.

[P_Shep]

You can store private keys on NFC tags. You can store a private key on anything that can hold text, including paper.

Only thing is, from scanning through that page, it looks like thats an NFC reader and not an NFC tag.

RFIDs hold just numbers / data, such as a public key.
NFC is like RFID but 2-way (hence the C for Communication), which can be used for signing a message with a private key and sending the response back.

[J-Norm]

I like the idea of a NFC device like this. I like the idea of it being all or nothing.

A 5BTC chip would show red for empty and green for full. It would also broadcast its public key and be willing to sign a challenge number to prove it really controls that key. That way you can check the balance of someone elses chip and confirm no trickery is going on.

It would also be able to sign a transaction of its full balance, but only if a switch or button is in the "spend" position.