Secure your gpg keys in style. By moving your keys to a hardware based smart-card, they are no longer accessible to malware on your machine. In fact, it's impossible for your machine to see the private key in any way. The keys never hits the primary system's memory or disk drive, thus they can't be stolen by conventional means.
In addition, the cards contain several features which make brute forcing impossible if someone steals your card. If an attacker enters three wrong passwords, the card will lock. If they enter invalid unlock passwords three times, the card will self-destruct, wiping the key from the device.
I've used similar keys and readers on Windows, Mac, and Linux without any problems.
(1) OpenPGP card with a SIM-style punch-out chip.
(1) Gemalto USB Shell Token.
The combination provides a thumb-drive sized device that will securely carry your keys.
I'll ship the combo anywhere in the US via USPS for 15 BTC, regardless of current exchange rate. If you want to use an established escrow service, that's fine with me. I can provide technical support on setup. If you can't get things to work, I'll refund the BTC if you return the items. You pay shipping for the return.