[mey]

How does this work if you are around town, lets say eating lunch?

[blueskin_]

You could get an RFID-blocking wallet (should anyway, really) and put the key in that.

I have one from http://difrwear.com/; I've tested it and it's never leaked any signal from cards inside; should work fine with keys too.

[na85]

OffPocket, perhaps.